| the surface-associated and secreted mope protein of methylococcus capsulatus (bath) responds to changes in the concentration of copper in the growth medium. | expression of surface-associated and secreted protein mope of the methanotrophic bacterium methylococcus capsulatus (bath) in response to the concentration of copper ions in the growth medium was investigated. the level of protein associated with the cells and secreted to the medium changed when the copper concentration in the medium varied and was highest in cells exposed to copper stress. | 2003 | 12676726 |
| a novel sterol 14alpha-demethylase/ferredoxin fusion protein (mccyp51fx) from methylococcus capsulatus represents a new class of the cytochrome p450 superfamily. | sterol 14alpha-demethylase encoded by cyp51 is a member of the cytochrome p450 (cyp) superfamily of enzymes and has been shown to have an essential role in sterol biosynthesis in eukaryotes, with orthologues recently being described in some bacteria. examination of the genome sequence data for the proteobacterium methylococcus capsulatus, a bacterial species known to produce sterol, revealed the presence of a single cyp with strong homology to cyp51, particularly to a form in mycobacterium tuber ... | 2002 | 12235134 |
| [study of nucleotide sequences of nifh genes in methanotrophic bacteria]. | using a previously developed primer system, nifh gene fragments 450 nucleotides long were amplified, cloned, and sequenced for representatives of nitrogen-fixing methanotrophic bacteria of the genera methylococcus, methylocystis and methylosinus. fragments of nifh genes were also detected and sequenced in representatives of the genera methylomonas and methylobacter, which were not considered diazotrophs until recently. phylogenetic analysis revealed remoteness of nifh genes sequences of methanot ... | 2002 | 12244720 |
| diversity of the particulate methane monooxygenase gene in methanotrophic samples from different rice field soils in china and the philippines. | methanotrophic bacteria play a crucial role in regulating the emission of ch4 from rice fields into the atmosphere. we investigated the ch4 oxidation activity together with the diversity of methanotrophic bacteria in ten rice field soils from different geographic locations. upon incubation of aerated soil slurries under 7% ch4, rates of ch4 oxidation increased after a lag phase of 1-4 days and reached values of 3-10 micromol d(-1) g-dw(-1) soil. the methanotrophic community was assayed by retrie ... | 2002 | 12353882 |
| the membrane-associated form of methane mono-oxygenase from methylococcus capsulatus (bath) is a copper/iron protein. | a protocol has been developed which permits the purification of a membrane-associated methane-oxidizing complex from methylococcus capsulatus (bath). this complex has approximately 5 fold higher specific activity than any purified particulate methane mono-oxygenase (pmmo) previously reported from m. capsulatus (bath). this efficiently functioning methane-oxidizing complex consists of the pmmo hydroxylase (pmmoh) and an unidentified component we have assigned as a potential pmmo reductase (pmmor) ... | 2003 | 12379148 |
| component b binding to the soluble methane monooxygenase hydroxylase by saturation-recovery epr spectroscopy of spin-labeled mmob. | spin-labeled cys89 of the soluble methane monooxygenase regulatory protein (mmob) from methylococcus capsulatus (bath) binds within 15 +/- 4 a of the hydroxylase (mmoh) diiron center, placing the mmob docking site in the mmoh "canyon" region on iron-coordinating helices e and f of the alpha-subunit. | 2002 | 12418885 |
| [stability of genetic markers in methane-oxidizing bacteria]. | a number of methylococcus thermophilus 111p clones have been obtained which have acquired resistance to tetracycline. the stability of maintenance of marker resistance in these clones and also in already designed methylomonas rubra 15sh mutants has been investigated. chromosomal markers resistance to antibiotics or formaldehyde were maintained in the marked strains methylococcus thermophilus 111p and methylomonas rubra 15sh after storage in nonselective conditions. the markers of resistance to a ... | 2002 | 12436866 |
| heterotrophic bacteria growing in association with methylococcus capsulatus (bath) in a single cell protein production process. | the methanotrophic bacterium methylococcus capsulatus (bath) grows on pure methane. however, in a single cell protein production process using natural gas as methane source, a bacterial consortium is necessary to support growth over longer periods in continuous cultures. in different bioreactors of norferm danmark a/s, three bacteria consistently invaded m. capsulatus cultures growing under semi-sterile conditions in continuous culture. these bacteria have now been identified as a not yet descri ... | 2002 | 12073128 |
| expression and characterization of ferredoxin and flavin adenine dinucleotide binding domains of the reductase component of soluble methane monooxygenase from methylococcus capsulatus (bath). | soluble methane monooxygenase (smmo) from methylococcus capsulatus (bath) catalyzes the selective oxidation of methane to methanol, the first step in the primary catabolic pathway of methanotrophic bacteria. a reductase (mmor) mediates electron transfer from nadh through its fad and [2fe-2s] cofactors to the dinuclear non-heme iron sites housed in a hydroxylase (mmoh). the structurally distinct [2fe-2s], fad, and nadh binding domains of mmor facilitated division of the protein into its functiona ... | 2002 | 12501207 |
| cofactor-independent oxygenation reactions catalyzed by soluble methane monooxygenase at the surface of a modified gold electrode. | soluble methane monooxygenase (smmo) is a three-component enzyme that catalyses dioxygen- and nad(p)h-dependent oxygenation of methane and numerous other substrates. oxygenation occurs at the binuclear iron active centre in the hydroxylase component (mmoh), to which electrons are passed from nad(p)h via the reductase component (mmor), along a pathway that is facilitated and controlled by the third component, protein b (mmob). we previously demonstrated that electrons could be passed to mmoh from ... | 2003 | 12542703 |
| multiple polypeptide forms observed in two-dimensional gels of methylococcus capsulatus (bath) polypeptides are generated during the separation procedure. | we have examined two-dimensional electrophoresis (2-de) gel maps of polypeptides from the gram-negative bacterium methylococcus capsulatus (bath) and found the same widespread trains of spots as often reported in 2-de gels of polypeptides of other gram-negative bacteria. some of the trains of polypeptides, both from the outer membrane and soluble protein fraction, were shown to be generated during the separation procedure of 2-de, and not by covalent post-translational modifications. the trains ... | 2003 | 12601748 |
| inhibition of membrane-bound methane monooxygenase and ammonia monooxygenase by diphenyliodonium: implications for electron transfer. | diphenyliodonium (dpi) is known to irreversibly inactivate flavoproteins. we have found that dpi inhibits both membrane-bound methane monooxygenase (pmmo) from methylococcus capsulatus and ammonia monooxygenase (amo) of nitrosomonas europaea. the effect of dpi on nadh-dependent pmmo activity in vitro is ascribed to inactivation of ndh-2, a flavoprotein which we proposed catalyzes reduction of the quinone pool by nadh. dpi is a potent inhibitor of type 2 nadh:quinone oxidoreductase (ndh-2), with ... | 2004 | 14761987 |
| modular broad-host-range expression vectors for single-protein and protein complex purification. | a set of modular broad-host-range expression vectors with various affinity tags (six-his-tag, flag-tag, strep-tag ii, t7-tag) was created. the complete nucleotide sequences of the vectors are known, and these small vectors can be mobilized by conjugation. they are useful in the purification of proteins and protein complexes from gram-negative bacterial species. the plasmids were easily customized for thiocapsa roseopersicina, rhodobacter capsulatus, and methylococcus capsulatus by inserting an a ... | 2004 | 14766546 |
| detection and localization of two hydrogenases in methylococcus capsulatus (bath) and their potential role in methane metabolism. | methylococcus capsulatus (bath) was shown to contain two distinct hydrogenases, a soluble hydrogenase and a membrane-bound hydrogenase. this is the first report of a membrane-bound hydrogenase in methanotrophs. both enzymes were expressed apparently constitutively under normal growth conditions. the soluble hydrogenase was capable of reducing nad(+) with molecular hydrogen. the activities of both soluble and particulate methane monooxygenases could be driven by molecular hydrogen. this confirmed ... | 2002 | 11807566 |
| positively charged amino acids are essential for electron transfer and protein-protein interactions in the soluble methane monooxygenase complex from methylococcus capsulatus (bath). | the soluble methane monooxygenase (smmo) complex from methylococcus capsulatus (bath) catalyses oxygen- and nad(p)h-dependent oxygenation of methane, propene, and other substrates. whole-complex smmo oxygenase activity requires all three smmo components: the hydroxylase, the reductase, and protein b. also, in the presence of hydrogen peroxide, the hydroxylase alone catalyzes substrate oxygenation via the peroxide shunt reaction. we investigated the effect of amine cross-linking on hydroxylase ac ... | 2002 | 11851404 |
| dioxygen activation in methane monooxygenase: a theoretical study. | using broken-symmetry unrestricted density functional theory, the mechanism of enzymatic dioxygen activation by the hydroxylase component of soluble methane monooxygenase (mmoh) is determined to atomic detail. after a thorough examination of mechanistic alternatives, an optimal pathway was identified. the diiron(ii) state h(red) reacts with dioxygen to give a ferromagnetically coupled diiron(ii,iii) h(superoxo) structure, which undergoes intersystem crossing to the antiferromagnetic surface and ... | 2004 | 14995216 |
| quantitative detection of methanotrophs in soil by novel pmoa-targeted real-time pcr assays. | methane oxidation in soils is mostly accomplished by methanotrophic bacteria. little is known about the abundance of methanotrophs in soils, since quantification by cultivation and microscopic techniques is cumbersome. comparison of 16s ribosomal dna and pmoa (alpha subunit of the particulate methane monooxygenase) phylogenetic trees showed good correlation and revealed five distinct groups of methanotrophs within the alpha and gamma subclasses of proteobacteria: the methylococcus group, the met ... | 2003 | 12732507 |
| [utilization of methane and carbon dioxide by symbiotrophic bacteria in gills of mytilidae (bathymodiolus) from the rainbow and logachev hydrothermal fields on the mid-atlantic ridge]. | bivalve mollusks bathymodiolus asoricus and bathymodiolus puteoserpentis collected from the rainbow and logachev hydrothermal fields during dives of mir 1 and mir 2 deep-sea manned submersibles were studied. rates of methane oxidation and carbon dioxide assimilation in mussel gill tissue were determined by radiolabel analysis. during oxidation of 14ch4, radiocarbon was detected in significant quantities not only in carbon dioxide but also in dissolved organic matter, most notably 14c-formate and ... | 2002 | 12449636 |
| formaldehyde dehydrogenase preparations from methylococcus capsulatus (bath) comprise methanol dehydrogenase and methylene tetrahydromethanopterin dehydrogenase. | in methylotrophic bacteria, formaldehyde is an important but potentially toxic metabolic intermediate that can be assimilated into biomass or oxidized to yield energy. previously reported was the purification of an nad(p)(+)-dependent formaldehyde dehydrogenase (fdh) from the obligate methane-oxidizing methylotroph methylococcus capsulatus (bath), presumably important in formaldehyde oxidation, which required a heat-stable factor (known as the modifin) for fdh activity. here, the major protein c ... | 2004 | 14993320 |
| the stereospecific hydroxylation of [2,2-2h2]butane and chiral dideuteriobutanes by the particulate methane monooxygenase from methylococcus capsulatus (bath). | experiments on cryptically chiral ethanes have indicated that the particulate methane monooxygenase (pmmo) from methylococcus capsulatus (bath) catalyzes the hydroxylation of ethane with total retention of configuration at the carbon center attacked. this result would seem to rule out a radical mechanism for the hydroxylation chemistry, at least as mediated by this enzyme. the interpretation of subsequent experiments on n-propane, n-butane, and n-pentane has been complicated by hydroxylation at ... | 2003 | 12909646 |
| [physiological activity of mixed cultures of methylcoccus capsulatus ukm b-3030 with bacillus megaterium ukm b-5723t and bacillus subtilis vkpm b-1489 on solid surface colonization]. | physiological activity of monoculture of methylococcus capsulatus ucm b-3030 and its mixed cultures with two bacilli species distinguished by proteolytical properties--bacillus megaterium ucm b-5723t and bacillus subtilis bk[symbol: see text]m b-4189 in terms of long-duration cultivation is investigated. it is shown, that the most active methane consumption by methanotrophic bacteria and their mixed cultures with bacilli under solid surface colonization occurred on the second-eighth day of culti ... | 2002 | 12664554 |
| the membrane-associated methane monooxygenase (pmmo) and pmmo-nadh:quinone oxidoreductase complex from methylococcus capsulatus bath. | improvements in purification of membrane-associated methane monooxygenase (pmmo) have resulted in preparations of pmmo with activities more representative of physiological rates: i.e., >130 nmol.min(-1).mg of protein(-1). altered culture and assay conditions, optimization of the detergent/protein ratio, and simplification of the purification procedure were responsible for the higher-activity preparations. changes in the culture conditions focused on the rate of copper addition. to document the p ... | 2003 | 13129946 |
| [remote monitoring control techniques for biological air disperse systems]. | described in the paper are the results of designing a combination-luminescence lidar for the automated express determination of the concentration and dynamic distribution of biological pollutants in the atmosphere. it was established as possible to detect simultaneously the signals of aerosols' luminescence and those of combined atmospheric nitrogen dispersion to ensure an effective monitoring of biological aerosols along the probing route. | 2004 | 15022547 |
| nifh and nifd phylogenies: an evolutionary basis for understanding nitrogen fixation capabilities of methanotrophic bacteria. | the ability to utilize dinitrogen as a nitrogen source is an important phenotypic trait in most currently known methanotrophic bacteria (mb). this trait is especially important for acidophilic mb, which inhabit acidic oligotrophic environments, highly depleted in available nitrogen compounds. phylogenetically, acidophilic mb are most closely related to heterotrophic dinitrogen-fixing bacteria of the genus beijerinckia: to further explore the phylogenetic linkage between these metabolically diffe ... | 2004 | 15133093 |
| determination by x-ray absorption spectroscopy of the fe-fe separation in the oxidized form of the hydroxylase of methane monooxygenase alone and in the presence of mmod. | the diiron active site in the hydroxylase of methylococcus capsulatus (bath) methane monooxygenase (mmoh) has been studied in the oxidized form by x-ray absorption spectroscopy (xas). previous investigations by xas and x-ray crystallography have identified two different distances (3.0 and 3.4 angstroms) between the two fe atoms in the dinuclear site. the present study has employed a systematic extended x-ray absorption fine structure (exafs) fitting methodology, utilizing known and simulated act ... | 2004 | 15257585 |
| nmr structure of the flavin domain from soluble methane monooxygenase reductase from methylococcus capsulatus (bath). | soluble methane monooxygenase (smmo) catalyzes the hydroxylation of methane by dioxygen to methanol, the first step in carbon assimilation by methanotrophs. this multicomponent system transfers electrons from nadh through a reductase component to the non-heme diiron center in the hydroxylase where o(2) is activated. the reductase component comprises three distinct domains, a [2fe-2s] ferredoxin domain along with fad- and nadh-binding domains. we report the solution structure of the reduced 27.6 ... | 2004 | 15379538 |
| genes involved in the copper-dependent regulation of soluble methane monooxygenase of methylococcus capsulatus (bath): cloning, sequencing and mutational analysis. | the key enzyme in methane metabolism is methane monooxygenase (mmo), which catalyses the oxidation of methane to methanol. some methanotrophs, including methylococcus capsulatus (bath), possess two distinct mmos. the level of copper in the environment regulates the biosynthesis of the mmo enzymes in these methanotrophs. under low-copper conditions, soluble mmo (smmo) is expressed and regulation takes place at the level of transcription. the structural genes of smmo were previously identified as ... | 2003 | 12855730 |
| quantitative proteomic analysis of metabolic regulation by copper ions in methylococcus capsulatus (bath). | copper ions switch the oxidation of methane by soluble methane monooxygenase to particulate methane monooxygenase in methylococcus capsulatus (bath). toward understanding the change in cellular metabolism related to this transcriptional and metabolic switch, we have undertaken genomic sequencing and quantitative comparative analysis of the proteome in m. capsulatus (bath) grown under different copper-to-biomass ratios by cleavable isotope-coded affinity tag technology. of the 682 proteins identi ... | 2004 | 15385566 |
| a challenge for 21st century molecular biology and biochemistry: what are the causes of obligate autotrophy and methanotrophy? | we assess the use to which bioinformatics in the form of bacterial genome sequences, functional gene probes and the protein sequence databases can be applied to hypotheses about obligate autotrophy in eubacteria. obligate methanotrophy and obligate autotrophy among the chemo- and photo-lithotrophic bacteria lack satisfactory explanation a century or more after their discovery. various causes of these phenomena have been suggested, which we review in the light of the information currently availab ... | 2004 | 15449607 |
| production of high-quality particulate methane monooxygenase in high yields from methylococcus capsulatus (bath) with a hollow-fiber membrane bioreactor. | in order to obtain particulate methane monooxygenase (pmmo)-enriched membranes from methylococcus capsulatus (bath) with high activity and in high yields, we devised a method to process cell growth in a fermentor adapted with a hollow-fiber bioreactor that allows easy control and quantitative adjustment of the copper ion concentration in nms medium over the time course of cell culture. this technical improvement in the method for culturing bacterial cells allowed us to study the effects of coppe ... | 2003 | 14526001 |
| domain engineering of the reductase component of soluble methane monooxygenase from methylococcus capsulatus (bath). | soluble methane monooxygenase (smmo) from methylococcus capsulatus (bath) is a three-component enzyme system that catalyzes the conversion of methane to methanol. a reductase (mmor), which contains [2fe-2s] and fad cofactors, facilitates electron transfer from nadh to the hydroxylase diiron active sites where dioxygen activation and substrate hydroxylation take place. by separately expressing the ferredoxin (mmorfd, mmor residues 1-98) and fad/nadh (mmor-fad, mmor residues 99-348) domains of the ... | 2004 | 14613937 |
| wide distribution of a novel pmoa-like gene copy among type ii methanotrophs, and its expression in methylocystis strain sc2. | experiments were conducted to determine if a novel pmoa-like gene (pmoa2) recently discovered in the methane-oxidizing bacterium methylocystis strain sc2 (p. f. dunfield, m. tchawa yimga, s. d. dedysh, u. berger, w. liesack, and j. heyer, fems microbiol. ecol. 41:17-26, 2002) is present in other methane-oxidizing bacteria (mob), and if it is expressed. a newly developed primer combination (pmoa206f-pmoa703b) allowed a differential detection of pmoa1 and pmoa2. by using this primer combination, w ... | 2003 | 12957949 |
| analysis of methanotrophic bacteria in movile cave by stable isotope probing. | movile cave is an unusual groundwater ecosystem that is supported by in situ chemoautotrophic production. the cave atmosphere contains 1-2% methane (ch4), although much higher concentrations are found in gas bubbles that keep microbial mats afloat on the water surface. as previous analyses of stable carbon isotope ratios have suggested that methane oxidation occurs in this environment, we hypothesized that aerobic methane-oxidizing bacteria (methanotrophs) are active in movile cave. to identify ... | 2004 | 14756876 |
| preparation and x-ray structures of metal-free, dicobalt and dimanganese forms of soluble methane monooxygenase hydroxylase from methylococcus capsulatus (bath). | a three-component soluble methane monooxygenase (smmo) enzyme system catalyzes the hydroxylation of methane to methanol at a carboxylate-bridged diiron center housed in the alpha-subunit of the hydroxylase (mmoh). catalysis is facilitated by the presence of a regulatory protein (mmob) and inhibited by mmod, a protein of unknown function encoded in the smmo operon. both mmob and mmod are presumed to bind to the same region of the mmoh alpha-subunit. a colorimetric method for monitoring removal of ... | 2004 | 15610020 |
| total structure characterization of unsaturated acidic phospholipids provided by vicinal di-hydroxylation of fatty acid double bonds and negative electrospray ionization mass spectrometry. | in the present work, the unsaturated fatty acid substituents of some phosphatidic acid, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol species were converted to their 1,2-di-hydroxy derivatives by oso(4). the subsequent electrospray ionization tandem low-energy mass spectrometry analysis of the deprotonated species allowed positional determination of the double bonds by the production of specific product-ions. the product-ions are formed by charge-remote and charge-proximate ... | 2005 | 15653363 |
| crystal structure of a membrane-bound metalloenzyme that catalyses the biological oxidation of methane. | particulate methane monooxygenase (pmmo) is an integral membrane metalloenzyme that catalyses the conversion of methane to methanol. knowledge of how pmmo performs this extremely challenging chemistry may have an impact on the use of methane as an alternative energy source by facilitating the development of new synthetic catalysts. we have determined the structure of pmmo from the methanotroph methylococcus capsulatus (bath) to a resolution of 2.8 a. the enzyme is a trimer with an alpha3beta3gam ... | 2005 | 15674245 |
| a genomic view of methane oxidation by aerobic bacteria and anaerobic archaea. | recent sequencing of the genome and proteomic analysis of a model aerobic methanotrophic bacterium, methylococcus capsulatus (bath) has revealed a highly versatile metabolic potential. in parallel, environmental genomics has provided glimpses into anaerobic methane oxidation by certain archaea, further supporting the hypothesis of reverse methanogenesis. | 2005 | 15693955 |
| a non-radical mechanism for methane hydroxylation at the diiron active site of soluble methane monooxygenase. | we propose a non-radical mechanism for the conversion of methane into methanol by soluble methane monooxygenase (smmo), the active site of which involves a diiron active center. we assume the active site of the mmoh(q) intermediate, exhibiting direct reactivity with the methane substrate, to be a bis(mu-oxo)diiron(iv) complex in which one of the iron atoms is coordinatively unsaturated (five-coordinate). is it reasonable for such a diiron complex to be formed in the catalytic reaction of smmo? t ... | 2003 | 12772310 |
| structural biology: methanol maker. | | 2005 | 15758981 |
| fourier transform infrared characterization of the azido complex of methane monooxygenase hydroxylase from methylococcus capsulatus (bath). | the azido complex formed in oxidized methane monooxygenase from methylococcus capsulatus (bath) was investigated with resonance raman and ftir techniques. these experiments show the presence of a nuas(nnn) at approximately 2077 cm-1 which splits to two components at 2059 and 2073 cm-1 with 15n14n2. the vibrational data are assigned to an azido complex bound terminally to one iron(iii) at the diiron center. when the azido complex is illuminated at 15 k, a new nuas(nnn) is observed at 2136 cm-1 wh ... | 2005 | 15783178 |
| meds and pocr are novel domains with a predicted role in sensing simple hydrocarbon derivatives in prokaryotic signal transduction systems. | we identify two conserved domains in diverse bacterial and archaeal signaling proteins. one of them, the meds domain, is typified by the dmcr protein from methylococcus and the other by the pocr protein of salmonella typhi. we provide evidence that both these domains are likely to sense simple hydrocarbon derivatives and transduce downstream signals on binding these ligands. the pocr ligand-binding domain is shown to contain a novel variant of the fold found in pas and gaf domains. the meds doma ... | 2005 | 15814558 |
| product bound structures of the soluble methane monooxygenase hydroxylase from methylococcus capsulatus (bath): protein motion in the alpha-subunit. | the soluble methane monooxygenase hydroxylase (mmoh) alpha-subunit contains a series of cavities that delineate the route of substrate entrance to and product egress from the buried carboxylate-bridged diiron center. the presence of discrete cavities is a major structural difference between mmoh, which can hydroxylate methane, and toluene/o-xylene monooxygenase hydroxylase (tomoh), which cannot. to understand better the functions of the cavities and to investigate how an enzyme designed for meth ... | 2005 | 15839679 |
| insights into the obligate methanotroph methylococcus capsulatus. | completion of the genome sequence of methylococcus capsulatus bath is an important event in molecular microbiology, and an achievement for which the authors deserve congratulation. m. capsulatus, along with other methanotrophs, has been the subject of intense biochemical and molecular study because of its role in the global carbon cycle: the conversion of biogenic methane to carbon dioxide. the methane monooxygenase enzymes that are central to this process also have high biotechnological potenti ... | 2005 | 15866035 |
| characterization of a prokaryotic haemerythrin from the methanotrophic bacterium methylococcus capsulatus (bath). | for a long time, the haemerythrin family of proteins was considered to be restricted to only a few phyla of marine invertebrates. when analysing differential protein expression in the methane-oxidizing bacterium, methylococcus capsulatus (bath), grown at a high and low copper-to-biomass ratio, respectively, we identified a putative prokaryotic haemerythrin expressed in high-copper cultures. haemerythrins are recognized by a conserved sequence motif that provides five histidines and two carboxyla ... | 2005 | 15885093 |
| phylogenetic and biochemical evidence for sterol synthesis in the bacterium gemmata obscuriglobus. | sterol biosynthesis is viewed primarily as a eukaryotic process, and the frequency of its occurrence in bacteria has long been a subject of controversy. two enzymes, squalene monooxygenase and oxidosqualene cyclase, are the minimum necessary for initial biosynthesis of sterols from squalene. in this work, 19 protein gene sequences for eukaryotic squalene monooxygenase and 12 protein gene sequences for eukaryotic oxidosqualene cyclase were compared with all available complete and partial prokaryo ... | 2003 | 14660793 |
| utility of environmental primers targeting ancient enzymes: methylotroph detection in lake washington. | methods have been explored for detection of methylotrophs in natural samples, using environmental primers based on genes involved in the tetrahydromethanopterin (h4mpt)-linked c1 transfer pathway. the underlying hypotheses were that the h4mpt-linked pathway is an ancient methylotrophy pathway, based on gene divergence, and that primers targeting more divergent genes will detect a broader variety of methylotrophs compared to the variety uncovered using probes and primers targeting highly conserve ... | 2004 | 15696380 |
| characterization and structural analysis of an active particulate methane monooxygenase trimer from methylococcus capsulatus (bath). | the oxidation of methane to methanol in methanotrophs is catalyzed by the enzyme methane monooxygenase (mmo). two distinct forms of this enzyme exist, a soluble cytoplasmic mmo (smmo) and a membrane-bound particulate form (pmmo). we describe here the biochemical characterization of a stable and active purified pmmo hydroxylase (pmmo-h) and report a three-dimensional (3d) structure, determined by electron microscopy and single-particle analysis at 23 a resolution. both biochemical and structural ... | 2005 | 16101279 |
| strain variability in the dna immigration control region (icr) of xylella fastidiosa. | the genome of the bacterium xylella fastidiosa contains four orfs (xf2721, xf2725, xf2739 and xf0295) related to the restriction modification type i system, ordinarily named r-m. this system belongs to the dna immigration control region (icr). each orf is related to different operon structures, which are homologues among themselves and with subunit hsd r from the endonuclease coding genes. in addition, these orfs are highly homologous to genes in pseudomonas aeruginosa, methylococcus capsulatus ... | 2006 | 16125907 |
| genomic insights into methanotrophy: the complete genome sequence of methylococcus capsulatus (bath). | methanotrophs are ubiquitous bacteria that can use the greenhouse gas methane as a sole carbon and energy source for growth, thus playing major roles in global carbon cycles, and in particular, substantially reducing emissions of biologically generated methane to the atmosphere. despite their importance, and in contrast to organisms that play roles in other major parts of the carbon cycle such as photosynthesis, no genome-level studies have been published on the biology of methanotrophs. we repo ... | 2004 | 15383840 |
| effect of methanobactin on the activity and electron paramagnetic resonance spectra of the membrane-associated methane monooxygenase in methylococcus capsulatus bath. | improvements in the purification of methanobactin (mb) from either methylosinus trichosporium ob3b(t) or methylococcus capsulatus bath resulted in preparations that stimulated methane-oxidation activity in both whole-cell and cell-free fractions of methylococcus capsulatus bath expressing the membrane-associated methane monooxygenase (pmmo). by using washed membrane factions with pmmo activities in the 290 nmol propylene oxidized min(-1) (mg protein)(-1) range, activities approaching 400 nmol pr ... | 2005 | 16207923 |
| reactions of the peroxo intermediate of soluble methane monooxygenase hydroxylase with ethers. | soluble methane monooxygenase (smmo) isolated from methylococcus capsulatus (bath) utilizes a carboxylate-bridged diiron center and dioxygen to catalyze the conversion of methane to methanol. previous studies revealed that a di(mu-oxo)diiron(iv) intermediate termed q is responsible for the catalytic activity with hydrocarbons. in addition, the peroxodiiron(iii) intermediate (h(peroxo)) that precedes q formation in the catalytic cycle has been demonstrated to react with propylene, but its reactiv ... | 2005 | 15898785 |
| a diet rich in phosphatidylethanolamine increases plasma homocysteine in mink: a comparison with a soybean oil diet. | the effects of high dietary levels of phosphatidylethanolamine (pe) on plasma concentrations of homocysteine (thcy) have not previously been studied. eighteen mink (mustela vison) studied were fed one of three diets during a 25 d period in a parallel-group design. the compared diets had 0, 17 and 67 % extracted lipids from natural gas-utilising bacteria (lngb), which were rich in pe. the group with 0 % lngb was fed a diet of 100 % soyabean oil (sb diet). phospholipids are the main lipid componen ... | 2005 | 16277769 |
| biochemical characterization of mmos, a sensor protein involved in copper-dependent regulation of soluble methane monooxygenase. | methane monooxygenase (mmo) enzymes catalyze the oxidation of methane to methanol in methanotrophic bacteria. several strains of methanotrophs, including methylococcus capsulatus (bath), express a membrane-bound or particulate mmo (pmmo) at high copper-to-biomass ratios and a soluble mmo (smmo) form when copper is limited. the mechanism of this "copper switch" is not understood. the mmos gene, located downstream of the smmo operon, encodes a sensor protein that is part of a two-component signali ... | 2006 | 16922494 |
| analysing the outer membrane subproteome of methylococcus capsulatus (bath) using proteomics and novel biocomputing tools. | high-resolution two-dimensional gel electrophoresis and mass spectrometry has been used to identify the outer membrane (om) subproteome of the gram-negative bacterium methylococcus capsulatus (bath). twenty-eight unique polypeptide sequences were identified from protein samples enriched in oms. only six of these polypeptides had previously been identified. the predictions from novel bioinformatic methods predicting beta-barrel outer membrane proteins (omps) and om lipoproteins were compared to p ... | 2006 | 16311759 |
| reactions of the diiron(iv) intermediate q in soluble methane monooxygenase with fluoromethanes. | soluble methane monooxygenases utilize a carboxylate-bridged diiron center and dioxygen to convert methane to methanol. a diiron(iv) oxo intermediate q is the active species for this process. alternative substrates and theoretical studies can help elucidate the mechanism. experimental results for reactions with derivatized methanes were previously modeled by a combination of quantum mechanical/molecular mechanical techniques and the model was extended to predict the relative reactivity of fluoro ... | 2005 | 16176805 |
| preparation and characterization of a (cu,zn)-pmmo from methylococcus capsulatus (bath). | we report the preparation of a (cu,zn)-particulate methane monooxygenase (pmmo) in which the bulk of the copper ions of the electron-transfer clusters (e-clusters) has been replaced by divalent zn ions. the cu and zn contents in the (cu,zn)-pmmo were determined by both inductively coupled plasma mass spectroscopy (icp-ms) and x-ray absorption k-edge spectroscopy. further characterization of the (cu,zn)-pmmo was provided by pmmo-activity assays as well as low-temperature electron paramagnetic res ... | 2004 | 15541502 |
| stopped-flow fourier transform infrared spectroscopy of nitromethane oxidation by the diiron(iv) intermediate of methane monooxygenase. | the hydroxylase component (mmoh) of soluble methane monooxygenase from methylococcus capsulatus (bath) was reduced to the diiron(ii) form and then allowed to react with dioxygen to generate the diiron(iv) intermediate q in the first phase of a double-mixing stopped-flow experiment. cd3no2 was then introduced in the second phase of the experiment, which was carried out in d2o at 25 degrees c. the kinetics of the reaction of the substrate with q were monitored by stopped-flow fourier transform inf ... | 2003 | 16220908 |
| characterization of root-associated methanotrophs from three freshwater macrophytes: pontederia cordata, sparganium eurycarpum, and sagittaria latifolia. | root-associated methanotrophic bacteria were enriched from three common aquatic macrophytes: pontederia cordata, sparganium eurycarpum, and sagittaria latifolia. at least seven distinct taxa belonging to groups i and ii were identified and presumptively assigned to the genera methylosinus, methylocystis, methylomonas, and methylococcus. four of these strains appeared to be novel on the basis of partial 16s ribosomal dna sequence analysis. the root-methanotroph association did not appear to be hi ... | 1998 | 16349515 |
| the ring-finger protein haprin: domains and function in the acrosome reaction. | the rbcc (ring finger, b-box type zinc finger, coiled-coil domain) motif family contains a large number of proteins implicated in many cellular processes, including vesicle exocytosis. the acrosome reaction, the sperm exocytotic event that is required for fertilization, involves essentially the same process of intracellular membrane fusions as vesicular exocytosis in somatic cells. we have previously isolated a haploid-germ-cell-specific gene designated haprin, which encodes a rbcc motif protein ... | 2005 | 16381605 |
| distinguishing nitrous oxide production from nitrification and denitrification on the basis of isotopomer abundances. | the intramolecular distribution of nitrogen isotopes in n2o is an emerging tool for defining the relative importance of microbial sources of this greenhouse gas. the application of intramolecular isotopic distributions to evaluate the origins of n2o, however, requires a foundation in laboratory experiments in which individual production pathways can be isolated. here we evaluate the site preferences of n2o produced during hydroxylamine oxidation by ammonia oxidizers and by a methanotroph, ammoni ... | 2006 | 16391101 |
| [features of solid materials' colonization by pure and mixed cultures of methanotrophs]. | the process of colonization of hydrophilic (glass) and hydrophobic (polysterene) carriers by pure cultures of methanotrophs methylocystis parvus ucm b-3490t, methylococcus capsulatus ucm b-3030, as well as by their cultures mixed with bacillus megaterium ucm b 5723t and pseudomonas putida vkpm b-4188 under the conditions efficient for methanotrophic bacteria. m. parvus demonstrated the highest intensity of this process on the above carriers owing to high hydrophobic cell surface. both methanotro ... | 2004 | 15456220 |
| diversity of soluble methane monooxygenase-containing methanotrophs isolated from polluted environments. | methanotrophs were enriched and isolated from polluted environments in canada and germany. enrichments in low copper media were designed to specifically encourage growth of soluble methane monooxygenase (smmo) containing organisms. the 10 isolates were characterized physiologically and genetically with one type i and nine type ii methanotrophs being identified. three key genes: 16s rrna; pmoa and mmox, encoding for the particulate and soluble methane monooxygenases respectively, were cloned from ... | 2006 | 16448499 |
| phenylacetylene reversibly inhibits the phenol hydroxylase of pseudomonas sp. cf600 at high concentrations but is oxidized at lower concentrations. | alkynes are mechanism-based inhibitors of several bacterial monooxygenases, including the soluble methane monooxygenase (smmo) of methylococcus capsulatus and the toluene o-monooxygenase (tom) of burkholderia cepacia g4. in this paper, we investigated the inhibition of the phenol hydroxylase of pseudomonas sp. cf600 by the alkyne phenylacetylene. growth of cf600 on phenol and phenol hydroxylase activity were inhibited by phenylacetylene concentrations greater than 1.0 mm. unlike other alkynes, w ... | 2006 | 16485115 |
| genome of methylobacillus flagellatus, molecular basis for obligate methylotrophy, and polyphyletic origin of methylotrophy. | along with methane, methanol and methylated amines represent important biogenic atmospheric constituents; thus, not only methanotrophs but also nonmethanotrophic methylotrophs play a significant role in global carbon cycling. the complete genome of a model obligate methanol and methylamine utilizer, methylobacillus flagellatus (strain kt) was sequenced. the genome is represented by a single circular chromosome of approximately 3 mbp, potentially encoding a total of 2,766 proteins. based on genom ... | 2007 | 17416667 |
| polarized atr-ftir spectroscopy of the membrane-embedded domains of the particulate methane monooxygenase. | the particulate methane monooxygenase (pmmo) of methylococcus capsulatus (bath) is an integral membrane protein that catalyzes the conversion of methane to methanol. to gain some insight into the structure-reactivity pattern of this protein, we have applied attenuated total reflection fourier transform infrared (atr-ftir) spectroscopy to investigate the secondary structure of the pmmo. the results showed that ca. 60% of the amino acid residues were structured as alpha-helices. about 80% of the p ... | 2004 | 15491135 |
| [reclassification of thermophylic methane-oxidizing bacteria with the use of sequence-analysis of 16s rrna genes]. | the authors have performed sequence-analysis of 16s rrna genes of thermophylic methane-oxidizing bacteria ucm b-3026, ucm b-3032, ucm b-3109, ucm b-3014 which were isolated from sludge pond of different regions in ukraine and deposited at ukrainian collection of microorganisms (ucm) as methylococcus thermophilus and "m. gracilis". a comparative analysis of 16s rrna gene sequences of the studied bacteria with those sequences of various strains of bacteria in the genbank databases has shown that t ... | 2006 | 16686213 |
| [comparative characterization of cultured methane-oxidizing bacteria by serological and molecular methods]. | three stable methane-oxidizing enrichment cultures, sb26, sb31, and sb31a were analyzed by transmission electron microscopy and by serological and molecular techniques. electron microscopy revealed the presence of both type i and type ii methanotrophs in sb31 and sb31a enrichments; only type ii methanotrophs were found in sb26 enrichment. methylosinus trichosporium was detected in all three enrichments by the application of species-specific antibodies. additionally, methylocystis echinoides was ... | 2006 | 16871808 |
| stable-isotope analysis of a combined nitrification-denitrification sustained by thermophilic methanotrophs under low-oxygen conditions. | to simulate growth conditions experienced by microbiota at o(inf2)-limited interfaces of organic matter in compost, an experimental system capable of maintaining dual limitations of oxygen and carbon for extended periods, i.e., a po(inf2)-auxostat, has been used. (sup15)n tracer studies on thermophilic (53(deg)c) decomposition processes occurring in manure-straw aggregates showed the emission of dinitrogen gas from the reactor as a result of simultaneous nitrification and denitrification at low ... | 1997 | 16535510 |
| three-dimensional structure determination of a protein supercomplex that oxidizes methane to formaldehyde in methylococcus capsulatus (bath). | the oxidation of methane to methanol in methanotrophs is catalyzed by the enzyme methane monooxygenase (mmo). two distinct forms of this enzyme exist, a soluble cytoplasmic mmo (smmo) and a membrane-bound particulate form (pmmo). the active protein complex termed pmmo-c was purified recently from methylococcus capsulatus (bath). the complex consists of pmmo hydroxylase and an additional component pmmo-r, which was proposed to be the reductase for the pmmo complex. further study of this complex h ... | 2006 | 17002291 |
| duplication of the mmox gene in methylosinus sporium: cloning, sequencing and mutational analysis. | the soluble methane monooxygenase (smmo) is a key enzyme for methane oxidation, and is found in only some methanotrophs, including methylosinus sporium 5. smmo expression is regulated at the level of transcription from a sigma(54) promoter by a copper-switch, and is only expressed when the copper-to-biomass ratio during growth is low. extensive phylogenetic and genetic analyses of smmos and other soluble di-iron monooxygenases reveal that these enzymes have only been acquired relatively recently ... | 2006 | 17005974 |
| inhibition of methane oxidation by methylococcus capsulatus with hydrochlorofluorocarbons and fluorinated methanes. | the inhibition of methane oxidation by cell suspensions of methylococcus capsulatus (bath) exposed to hydrochlorofluorocarbon 21 (hcfc-21; difluorochloromethane [chf(inf2)cl]), hcfc-22 (fluorodichloromethane [chfcl(inf2)]), and various fluorinated methanes was investigated. hcfc-21 inhibited methane oxidation to a greater extent than hcfc-22, for both the particulate and soluble methane monooxygenases. among the fluorinated methanes, both methyl fluoride (ch(inf3)f) and difluoromethane (ch(inf2) ... | 1997 | 16535662 |
| planktonic and sediment-associated aerobic methanotrophs in two seep systems along the north american margin. | methane vents are of significant geochemical and ecological importance. notable progress has been made toward understanding anaerobic methane oxidation in marine sediments; however, the diversity and distribution of aerobic methanotrophs in the water column are poorly characterized. both environments play an essential role in regulating methane release from the oceans to the atmosphere. in this study, the diversity of particulate methane monooxygenase (pmoa) and 16s rrna genes from two methane v ... | 2008 | 18487407 |
| [the binuclear iron site of the membrane-bound methane hydroxylase from methylococcus capsulatus (strain m)]. | the particulate membrane-bound methane hydroxylase (pmmoh) was isolated from methane-oxidizing cells of methylococcus capsulatus (strain m). at sds page, pmmoh displays three bands: 47 (alpha), 27 (beta), and 25 kda (gamma). the esr spectrum of pmmoh incubated with hydrogen peroxide (final concentration 20 mm) at 4 degrees c exhibited, along with the copper signal of type i with g = 2.05, signals of cytochrome with g = 3.0 and of high-spin ferriheme with g = 6.00. after incubation at -30 degrees ... | 2008 | 18522275 |
| optimization of solubilization and purification procedures for the hydroxylase component of membrane-bound methane monooxygenase from methylococcus capsulatus strain m. | the hydroxylase component of membrane-bound (particulate) methane monooxygenase (pmmo) from methylococcus capsulatus strain m was isolated and purified to homogeneity. the pmmo molecule comprises three subunits of molecular masses 47, 26, and 23 kd and contains three copper atoms and one iron atom. in solution the protein exists as a stable oligomer of 660 kd with possible subunit composition (alpha beta gamma)6. mass spectroscopy shows high homology of the purified protein with methane monooxyg ... | 2006 | 17223785 |
| [effect of substances which change the proton-motive force on activity of methane microbe oxygenation]. | high extracellular concentration of k+ stimulated methane oxygenation with methylomonas rubra 15 [russian character: see text], methylococcus thermophilus 111 [russian character: see text] and methylococcus capsulatus 494 at neutral value of ph. that was determined by k+ arrival to the cells at neutral medium ph that resulted in the increase of ph difference between the exterior and interior sides of the membrane (aph) and, respectively, in the increase of the methane oxygenation rate. thus, met ... | 2006 | 17243361 |
| the fine structure of methylococcus capsulatus. | the fine structure of methylococcus capsulatus is described. particular emphasis is focused on the intracytoplasmic membrane system which is organized as a stacked array of flattened saccules. each saccule is limited by a 75 a unit membrane and lies in close apposition to adjacent saccules. methylococcus capsulatus is an obligate methylotroph whose sole source of carbon and energy is methane (or methanol). in this study methane oxidation is demonstrated for the first time in a cell-free system. ... | 1970 | 18631529 |
| desaturase reactions complicate the use of norcarane as a mechanistic probe. unraveling the mixture of twenty-plus products formed in enzyme-catalyzed oxidations of norcarane. | norcarane, bicyclo[4.1.0]heptane, has been widely used as a mechanistic probe in studies of oxidations catalyzed by several iron-containing enzymes. we report here that, in addition to oxygenated products, norcarane is also oxidized by iron-containing enzymes in desaturase reactions that give 2-norcarene and 3-norcarene. furthermore, secondary products from further oxidation reactions of the norcarenes are produced in yields that are comparable to those of the minor products from oxidation of th ... | 2007 | 17288366 |
| products from enzyme-catalyzed oxidations of norcarenes. | recent studies revealed that norcarane (bicyclo[4.1.0]heptane) is oxidized to 2-norcarene (bicyclo[4.1.0]-hept-2-ene) and 3-norcarene (bicyclo[4.1.0]hept-3-ene) by iron-containing enzymes and that secondary oxidation products from the norcarenes complicate mechanistic probe studies employing norcarane as the substrate (newcomb, m.; chandrasena, r. e. p.; lansakara-p., d. s. p.; kim, h.-y.; lippard, s. j.; beauvais, l. g.; murray, l. j.; izzo, v.; hollenberg, p. f.; coon, m. j. j. org. chem. 2007 ... | 2007 | 17288367 |
| cytochromes p460 and c'-beta; a new family of high-spin cytochromes c. | cytochromes-p460 of nitrosomonas europaea and methylococcus capsulatus (bath), and the cytochrome c' of m. capsulatus, believed to be involved in binding or transformation of n-oxides, are shown to represent an evolutionarily related new family of monoheme, approximately 17kda, cytochromes c found in the genomes of diverse proteobacteria. all members of this family have a predicted secondary structure predominantly of beta-sheets in contrast to the predominantly alpha-helical cytochromes c' foun ... | 2007 | 17292891 |
| complement activation and cytokine response by bioprotein, a bacterial single cell protein. | the bacterial single cell protein (bscp), bioprotein, is dried bacterial mass derived from fermentation of the gram negative bacteria methylococcus capsulatus, used for animal and fish feed. workers in this industry suffer frequently from pulmonary and systemic symptoms which may be induced by an inflammatory reaction. the aim of the present study was to examine the effect of bscp on inflammation in vitro as evaluated by complement activation and cytokine production. human serum was incubated wi ... | 2007 | 17302729 |
| the biochemistry of methane oxidation. | methanotrophic bacteria oxidize methane to methanol in the first step of their metabolic pathway. two forms of methane monooxygenase (mmo) enzymes catalyze this reaction: soluble mmo (smmo) and membrane-bound or particulate mmo (pmmo). pmmo is expressed when copper is available, and its active site is believed to contain copper. whereas smmo is well characterized, most aspects of pmmo biochemistry remain unknown and somewhat controversial. this review emphasizes advances in the past two to three ... | 2007 | 17328677 |
| identification of a copper-repressible c-type heme protein of methylococcus capsulatus (bath). a member of a novel group of the bacterial di-heme cytochrome c peroxidase family of proteins. | genomic sequencing of the methanotrophic bacterium, methylococcus capsulatus (bath), revealed an open reading frame (mca2590) immediately upstream of the previously described mope gene (mca2589). sequence analyses of the deduced amino acid sequence demonstrated that the mca2590-encoded protein shared significant, but restricted, sequence similarity to the bacterial di-heme cytochrome c peroxidase (bccp) family of proteins. two putative c-type heme-binding motifs were predicted, and confirmed by ... | 2005 | 16336269 |
| the active methanotrophic community in hydromorphic soils changes in response to changing methane concentration. | methanotrophic communities were studied in several periodically water-saturated gleyic soils. when sampled, each soil had an oxic upper layer and consumed methane from the atmosphere (at 1.75 ppmv). in most gleyic soils the k(m(app)) values for methane were between 70 and 800 ppmv. these are higher than most values observed in dry upland soils, but lower than those measured in wetlands. based on cultivation-independent retrieval of the pmoa-gene and quantification of partial pmoa gene sequences, ... | 2006 | 16423018 |
| biochemical characterization of isocitrate dehydrogenase from methylococcus capsulatus reveals a unique nad+-dependent homotetrameric enzyme. | the gene encoding isocitrate dehydrogenase (idh) of methylococcus capsulatus (mcidh) was cloned and overexpressed in escherichia coli. the purified enzyme was nad+-dependent with a thermal optimum for activity at 55-60 degrees c and an apparent midpoint melting temperature (tm) of 70 degrees c. analytical ultracentrifugation (auc) revealed a homotetrameric state, and mcidh thus represents the first homotetrameric nad+-dependent idh that has been characterized. based on a structural alignment of ... | 2007 | 17160675 |
| characterization of the particulate methane monooxygenase metal centers in multiple redox states by x-ray absorption spectroscopy. | the integral membrane enzyme particulate methane monooxygenase (pmmo) converts methane, the most inert hydrocarbon, to methanol under ambient conditions. the 2.8-a resolution pmmo crystal structure revealed three metal sites: a mononuclear copper center, a dinuclear copper center, and a nonphysiological mononuclear zinc center. although not found in the crystal structure, solution samples of pmmo also contain iron. we have used x-ray absorption spectroscopy to analyze the oxidation states and co ... | 2006 | 16999437 |
| effect of afforestation and reforestation of pastures on the activity and population dynamics of methanotrophic bacteria. | we investigated the effect of afforestation and reforestation of pastures on methane oxidation and the methanotrophic communities in soils from three different new zealand sites. methane oxidation was measured in soils from two pine (pinus radiata) forests and one shrubland (mainly kunzea ericoides var. ericoides) and three adjacent permanent pastures. the methane oxidation rate was consistently higher in the pine forest or shrubland soils than in the adjacent pasture soils. a combination of pho ... | 2007 | 17574997 |
| biochemical and molecular characterization of methanotrophs in soil from a pristine new zealand beech forest. | methane (ch4) oxidation and the methanotrophic community structure of a pristine new zealand beech forest were investigated using biochemical and molecular methods. phospholipid-fatty acid-stable-isotope probing (plfa-sip) was used to identify the active population of methanotrophs in soil beneath the forest floor, while terminal-restriction fragment length polymorphism (t-rflp) and cloning and sequencing of the pmoa gene were used to characterize the methanotrophic community. plfa-sip suggested ... | 2007 | 17696992 |
| improved analysis of membrane protein by pvdf-aided, matrix-assisted laser desorption/ionization mass spectrometry. | characterization of membrane proteins remains an analytical challenge because of difficulties associated with tedious isolation and purification. this study presents the utility of the polyvinylidene difluoride (pvdf) membrane for direct sub-proteome profiling and membrane protein characterization by matrix-assisted laser desorption/ionization mass spectrometry (maldi-ms). the hydrophobic adsorption of protein, particularly membrane proteins, on the pvdf surface enables efficient on-pvdf washing ... | 2006 | 17723354 |
| effect of temperature on composition of the methanotrophic community in rice field and forest soil. | temperature change affects methane consumption in soil. however, there is no information on possible temperature control of methanotrophic bacterial populations. therefore, we studied ch(4) consumption and populations of methanotrophs in an upland forest soil and a rice field soil incubated at different temperatures between 5 and 45 degrees c for up to 40 days. potential methane consumption was measured at 4% ch(4). the temporal progress of ch(4) consumption indicated growth of methanotrophs. bo ... | 2007 | 17725622 |
| microbial oxidation of gaseous hydrocarbons: production of methylketones from corresponding n-alkanes by methane-utilizing bacteria. | cell suspensions of methane-utilizing bacteria grown on methane oxidized n-alkanes (propane, butane, pentane, hexane) to their corresponding methylketones (acetone, 2-butanone, 2-pentanone, 2-hexanone). the product methylketones accumulated extracellularly. the rate of production of methylketones varied with the organism used for oxidation; however, the average rate of acetone, 2-butanone, 2-pentanone, and 2-hexanone production was 1.2, 1.0, 0.15, and 0.025 mumol/h per 5.0 mg of protein in cell ... | 1980 | 16345538 |
| evaluation of methyl fluoride and dimethyl ether as inhibitors of aerobic methane oxidation. | methyl fluoride (mf) and dimethyl ether (dme) were effective inhibitors of aerobic methanotrophy in a variety of soils. mf and dme blocked consumption of ch(4) as well as the oxidation of ch(4) to co(2), but neither mf nor dme affected the oxidation of [c]methanol or [c]formate to co(2). cooxidation of ethane and propane by methane-oxidizing soils was also inhibited by mf. nitrification (ammonia oxidation) in soils was inhibited by both mf and dme. production of n(2)o via nitrification was inhib ... | 1992 | 16348771 |
| the c-terminal aqueous-exposed domain of the 45 kda subunit of the particulate methane monooxygenase in methylococcus capsulatus (bath) is a cu(i) sponge. | the crystal structure of the particulate methane monooxygenase (pmmo) from methylococcus capsulatus (bath) has been reported recently [lieberman, r. l., and rosenzweig, a. c. (2005) crystal structure of a membrane-bound metalloenzyme that catalyses the biological oxidation of methane, nature 434, 177-182]. subsequent work has shown that the preparation on which the x-ray analysis is based might be missing many of the important metal cofactors, including the putative trinuclear copper cluster at ... | 2007 | 17985930 |
| lanosterol biosynthesis in the prokaryote methylococcus capsulatus: insight into the evolution of sterol biosynthesis. | a putative operon containing homologues of essential eukaryotic sterol biosynthetic enzymes, squalene monooxygenase and oxidosqualene cyclase, has been identified in the genome of the prokaryote methylococcus capsulatus. expression of the squalene monooxygenase yielded a protein associated with the membrane fraction, while expression of oxidosqualene cyclase yielded a soluble protein, contrasting with the eukaryotic enzyme forms. activity studies with purified squalene monooxygenase revealed a c ... | 2007 | 17567593 |
| an oxidized tryptophan facilitates copper binding in methylococcus capsulatus-secreted protein mope. | proteins can coordinate metal ions with endogenous nitrogen and oxygen ligands through backbone amino and carbonyl groups, but the amino acid side chains coordinating metals do not include tryptophan. here we show for the first time the involvement of the tryptophan metabolite kynurenine in a protein metal-binding site. the crystal structure to 1.35 angstroms of mope* from the methane-oxidizing methylococcus capsulatus (bath) provided detailed information about its structure and mononuclear copp ... | 2008 | 18348978 |
| oxidase, superoxide dismutase, and hydrogen peroxide reductase activities of methanobactin from types i and ii methanotrophs. | methanobactin (mb) is a copper-binding chromopeptide that appears to be involved in oxidation of methane by the membrane-associated or particulate methane monooxygenase (pmmo). to examine this potential physiological role, the redox and catalytic properties of mb from three different methanotrophs were examined in the absence and presence of o(2). metal free mb from the type ii methanotroph methylosinus trichosporium ob3b, but not from the type i methanotrophs methylococcus capsulatus bath or me ... | 2008 | 18372044 |
| sterol biosynthesis by a prokaryote: first in vitro identification of the genes encoding squalene epoxidase and lanosterol synthase from methylococcus capsulatus. | sterol biosynthesis by prokaryotic organisms is very rare. squalene epoxidase and lanosterol synthase are prerequisite to cyclic sterol biosynthesis. these two enzymes, from the methanotrophic bacterium methylococcus capsulatus, were functionally expressed in escherichia coli. structural analyses of the enzymatic products indicated that the reactions proceeded in a complete regio- and stereospecific fashion to afford (3s)-2,3-oxidosqualene from squalene and lanosterol from (3s)-2,3-oxidosqualene ... | 2007 | 17928701 |
| isolation, purification and characterization of hemerythrin from methylococcus capsulatus (bath). | earlier work from our laboratory has indicated that a hemerythrin-like protein was over-produced together with the particulate methane monooxygenase (pmmo) when methylococcus capsulatus (bath) was grown under high copper concentrations. a homologue of hemerythrin had not previously been found in any prokaryote. to confirm its identity as a hemerythrin, we have isolated and purified this protein by ion-exchange, gel-filtration and hydrophobic interaction chromatography, and characterized it by ma ... | 2008 | 18397812 |
| the metal centers of particulate methane monooxygenase from methylosinus trichosporium ob3b. | particulate methane monooxygenase (pmmo) is a membrane-bound metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria. the nature of the pmmo active site and the overall metal content are controversial, with spectroscopic and crystallographic data suggesting the presence of a mononuclear copper center, a dinuclear copper center, a trinuclear center, and a diiron center or combinations thereof. most studies have focused on pmmo from methylococcus capsulatus (bath). pmmo from a s ... | 2008 | 18540635 |
| effect of temperature and pressure on growth and methane utilization by several methanotrophic cultures. | several methanotrophic microorganisms, i.e., methylococcus capsulatus (bath), methylomonas albus (bg-8), methylosinus trichosporium ob3b, and methylocystis parvus (obbp), were evaluated for growth and methane utilization. the effect of temperature was examined in the range of 25 to 45 degrees c for growth and methane utilization. the temperature variations (25-35 degrees c) had minimal effect on growth of m. albus and m. parvus. methane consumption varied at different temperatures with a maximum ... | 1998 | 18576037 |
| transcription of nitrification genes by the methane-oxidizing bacterium, methylococcus capsulatus strain bath. | methylococcus capsulatus strain bath, a methane-oxidizing bacterium, and ammonia-oxidizing bacteria (aob) carry out the first step of nitrification, the oxidation of ammonia to nitrite, through the intermediate hydroxylamine. aob use hydroxylamine oxidoreductase (hao) to produce nitrite. m. capsulatus bath was thought to oxidize hydroxylamine with cytochrome p460 (cytl), until the recent discovery of an hao gene in its genome. we used quantitative pcr analyses of cdna from m. capsulatus bath inc ... | 2008 | 18650926 |