Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| chloromethane-induced genes define a third c1 utilization pathway in methylobacterium chloromethanicum cm4. | methylobacterium chloromethanicum cm4 is an aerobic alpha-proteobacterium capable of growth with chloromethane as the sole carbon and energy source. two proteins, cmua and cmub, were previously purified and shown to catalyze the dehalogenation of chloromethane and the vitamin b12-mediated transfer of the methyl group of chloromethane to tetrahydrofolate. three genes located near cmua and cmub, designated metf, fold and puru and encoding homologs of methylene tetrahydrofolate (methylene-h4folate) ... | 2002 | 12057941 |
| dichloromethane metabolism and c1 utilization genes in methylobacterium strains. | the ability of methylotrophic alpha-proteobacteria to grow with dichloromethane (dcm) as source of carbon and energy has long been thought to depend solely on a single cytoplasmic enzyme, dcm dehalogenase, which converts dcm to formaldehyde, a central intermediate of methylotrophic growth. the gene dcma encoding dcm dehalogenase of methylobacterium dichloromethanicum dm4 was expressed from a plasmid in closely related methylobacterium strains lacking this enzyme. the ability to grow with dcm cou ... | 2002 | 12055310 |
| methylobacterium suomiense sp. nov. and methylobacterium lusitanum sp. nov., aerobic, pink-pigmented, facultatively methylotrophic bacteria. | two aerobic, pink-pigmented, facultatively methylotrophic bacteria, strains f20t and rxm(t), are described taxonomically. on the basis of their phenotypic and genotypic properties, the isolates are proposed as novel species of the genus methylobacterium, methylobacterium suomiense sp. nov. (type strain f20t = vkm b-2238t = ncimb 13778t) and methylobacterium lusitanum sp. nov. (type strain rxmt = vkm b-2239t = ncimb 13779t). | 2002 | 12054237 |
| [methanotrophic communities in the soils of russian northern taiga and subarctic tundra]. | the pcr analysis of dna extracted from soil samples taken in russian northern taiga and subarctic tundra showed that the dna extracts contain genes specific to methanotrophic bacteria, i.e., the mmox gene encoding the conserved alpha-subunit of the hydroxylase component of soluble methane monooxygenase, the pmoa gene encoding the alpha-subunit of particulate methane monooxygenase, and the mxaf gene encoding the alpha-subunit of methanol dehydrogenase. pcr analysis with group-specific primers als ... | 2002 | 12024830 |
| a review of bacterial methyl halide degradation: biochemistry, genetics and molecular ecology. | methyl halide-degrading bacteria are a diverse group of organisms that are found in both terrestrial and marine environments. they potentially play an important role in mitigating ozone depletion resulting from methyl chloride and methyl bromide emissions. the first step in the pathway(s) of methyl halide degradation involves a methyltransferase and, recently, the presence of this pathway has been studied in a number of bacteria. this paper reviews the biochemistry and genetics of methyl halide ... | 2002 | 12010126 |
| population dynamics of type i and ii methanotrophic bacteria in rice soils. | methane-oxidizing bacteria (methanotrophs) consume a significant but variable fraction of greenhouse-active methane gas produced in wetlands and rice paddies before it can be emitted to the atmosphere. temporal and spatial dynamics of methanotroph populations in california rice paddies were quantified using phospholipid biomarker analyses in order to evaluate the relative importance of type i and type ii methanotrophs with depth and in relation to rice roots. methanotroph population fluctuations ... | 2002 | 12000315 |
| electronic excitations of biomolecules studied by quantum chemistry. | significant methodological advances have been made over the past ten years in developing reliable quantum chemical methods for the treatment of electronically excited states. these methods can nowadays be used routinely by the experienced researcher to accurately compute excitation spectra of medium-sized organic molecules; results have been reported for several popular photobiological systems, including green fluorescent protein. first steps are currently being taken to account for the solvochr ... | 2002 | 11959493 |
| a new molecular mechanics force field for the oxidized form of blue copper proteins. | a molecular mechanics force field for blue copper proteins has been developed, based on a rigid potential energy surface scan of the cu(ii)/his/his/cys/met chromophore, using dft (b3lyp) calculations and the amber force field for the protein backbone. the strain-energy-minimized structures of the model chromophore alone are in excellent agreement with the dft-optimized structure, and those of the entire set of cupredoxins (five structures are considered) are, within the experimental error limits ... | 2002 | 11948587 |
| [ethanol formation by methane-utilizing bacteria at ethane co-metabolism]. | it was established, that edta (1.0 mm) and formamide (100 mm) are inhibitors of methanol dehydrogenase in methylobacter luteus 12b, methylomonas rubra 15sh and methylococcus thermophilus 111p. the investigated strains co-metabolised ethane with the use of formate as the co-substrate. the application of formamide (or edta) as inhibitors of methanol dehydrogenase prevented from further transformation of ethanol and resulted in accumulation of extracellular ethanol. it was shown, that m. rubra 15sh ... | 2002 | 11944346 |
| a general method for determining the electron self-exchange rates of blue copper proteins by longitudinal nmr relaxation. | a general nmr method is presented that allows a precise determination of the second-order rate constant, k(ese), for the electron self-exchange in blue copper proteins, from the longitudinal relaxation rates of the nuclei in the protein. the method relies on the use of partly oxidized (paramagnetic) samples of the protein. in contrast to previous nmr approaches for the determination of electron self-exchange rates, the applicability of the method extends beyond the slow-exchange limit, k(ese)c < ... | 2002 | 11942848 |
| stoichiometric model for evaluating the metabolic capabilities of the facultative methylotroph methylobacterium extorquens am1, with application to reconstruction of c(3) and c(4) metabolism. | a stoichiometric model of central metabolism was developed based on new information regarding metabolism in this bacterium to evaluate the steady-state growth capabilities of the serine cycle facultative methylotroph methylobacterium extorquens am1 during growth on methanol, succinate, and pyruvate. the model incorporates 20 reversible and 47 irreversible reactions, 65 intracellular metabolites, and experimentally-determined biomass composition. the flux space for this underdetermined system of ... | 2002 | 11920446 |
| molecular and regulatory properties of leucoplast pyruvate kinase from brassica napus (rapeseed) suspension cells. | plastidic pyruvate kinase (pk(p)) from brassica napus suspension cells was purified 431-fold to a final specific activity of 28 micromol phosphoenolpyruvate (pep) utilized/min/mg protein. sds-page, immunoblot and gel filtration analyses indicated that this pk(p) exists as a 380-kda heterohexamer composed of equal proportions of 64- (alpha-subunit) and 58-kda (beta-subunit) polypeptides. the n-terminal sequence of the pk(p) alpha- and beta-subunits exhibited maximal identity with the correspondin ... | 2002 | 11913971 |
| [new evidence for the ability of methylobacteria and methanotrophs to synthesize auxins]. | 2002 | 11910802 | |
| a model for the thermal unfolding of amicyanin. | in the present study the thermal unfolding of amicyanin has been addressed using differential scanning calorimetry, fluorescence emission, optical density, circular dichroism and electron paramagnetic resonance. the combined use of these techniques has allowed us to assess, during unfolding of the protein, its global conformational changes in relationship to the local structural modifications occurring in the copper environment and close to the fluorescent chromophore trp46 of the protein. the t ... | 2002 | 11908848 |
| an outer-sphere hydrogen-bond network constrains copper coordination in blue proteins. | in azurins and other blue copper proteins with relatively low reduction potentials (e(0) [cu(ii)/cu(i)]<400 mv vs. normal hydrogen electrode), the folded polypeptide framework constrains both copper(ii) and copper(i) in such a way as to tune the reduction potentials to values that differ greatly from those for most copper complexes. largely conserved networks of hydrogen bonds organize and lock the rest of the folded protein structure to a loop that contains three of the ligands to copper. chang ... | 2002 | 11897353 |
| purification and characterization of the methylene tetrahydromethanopterin dehydrogenase mtdb and the methylene tetrahydrofolate dehydrogenase fold from hyphomicrobium zavarzinii zv580. | recently, it has been shown that heterotrophic methylotrophic proteobacteria contain tetrahydrofolate (h(4)f)- and tetrahydromethanopterin (h(4)mpt)-dependent enzymes. here we report on the purification of two methylene tetrahydropterin dehydrogenases from the methylotroph hyphomicrobium zavarzinii zv580. both dehydrogenases are composed of one type of subunit of 31 kda. one of the dehydrogenases is nad(p)-dependent and specific for methylene h(4)mpt (specific activity: 680 u/mg). its n-terminal ... | 2002 | 11889483 |
| trna is the source of low-level trans-zeatin production in methylobacterium spp. | pink-pigmented facultatively methylotrophic bacteria (ppfms), classified as methylobacterium spp., are persistent colonizers of plant leaf surfaces. reports of ppfm-plant dialogue led us to examine cytokinin production by ppfms. using immunoaffinity and high-performance liquid chromatography (hplc) purification, we obtained 22 to 111 ng of trans-zeatin per liter from culture filtrates of four ppfm leaf isolates (from arabidopsis, barley, maize, and soybean) and of a methylobacterium extorquens t ... | 2002 | 11889088 |
| plants in the pink: cytokinin production by methylobacterium. | 2002 | 11889085 | |
| glyoxylate regeneration pathway in the methylotroph methylobacterium extorquens am1. | most serine cycle methylotrophic bacteria lack isocitrate lyase and convert acetyl coenzyme a (acetyl-coa) to glyoxylate via a novel pathway thought to involve butyryl-coa and propionyl-coa as intermediates. in this study we have used a genome analysis approach followed by mutation to test a number of genes for involvement in this novel pathway. we show that methylmalonyl-coa mutase, an r-specific crotonase, isobutyryl-coa dehydrogenase, and a gtpase are involved in glyoxylate regeneration. we a ... | 2002 | 11872727 |
| methylobacterium bacteremia in aids. | 1998 | 11864300 | |
| the ph-dependent redox inactivation of amicyanin from paracoccus versutus as studied by rapid protein-film voltammetry. | the redox properties of the blue copper protein amicyanin have been studied with slow and fast scan protein-film cyclic voltammetry. at slow scan rates, which reveal the thermodynamics of the redox reactions, the reduction potential of amicyanin depends on ph in a sigmoidal manner, and the data can be analysed in terms of electron transfer being coupled to a single protonatable group with pka(red)=6.3 and pka(ox) < or = 3.2 at 22 degrees c. voltammetry at higher scan rates reveals the kinetics a ... | 2002 | 11862545 |
| recurrent methylobacterium mesophilicum sepsis associated with haemodialysis. | methylobacterium mesophilicum is an environmental organism that has infrequently been implicated as a human pathogen. most reported cases are in immunocompromised hosts. the natural ecology of this organism is related to vegetation or soil. we report the case of a 51-year-old man who developed a recurrent bacteraemia with this organism while receiving haemodialysis through an indwelling intravascular catheter. the literature on the clinical significance of this organism is reviewed together with ... | 2001 | 11827428 |
| new monomeric cobalt(ii) and zinc(ii) complexes of a mixed n,s(alkylthiolate) ligand: model complexes of (his)(his)(cys) metalloprotein active sites. | the new n(2)s(alkylthiolate) ligand 2-methyl-1-[methyl-(2-pyridin-2-ylethyl)amino]propane-2-thiolate, path (1), has been prepared and reacted with zinc(ii) and cobalt(ii) to give the monomeric complexes [(path)znbr] (2), [(path)znncs] (3), [(path)cobr] (4), and [(path)concs] (5). the molecular structures of 4 and 5 have been determined by x-ray diffraction. each complex displays a distorted tetrahedral geometry at the metal center, with the path ligand providing the n(2)s(alkylthiolate) donors. ... | 2002 | 11800612 |
| [aerobic methylotroph bacteria as phytosymbionts]. | this paper deals with the physiological, biochemical, and molecular genetic aspects of the interaction of aerobic methylotrophic bacteria with plants by means of phytohormones (such as cytokinins and auxins) and other physiologically active substances (vitamins, exopolysaccharides, bioprotectants). the state of the art and the prospects of research in the field of bacteria-plant interactions and the application of aerobic methylotrophs in plant biotechnology is discussed. | 2001 | 11785128 |
| duplicate copies of genes encoding methanesulfonate monooxygenase in marinosulfonomonas methylotropha strain tr3 and detection of methanesulfonate utilizers in the environment. | marinosulfonomonas methylotropha strain tr3 is a marine methylotroph that uses methanesulfonic acid (msa) as a sole carbon and energy source. the genes from m. methylotropha strain tr3 encoding methanesulfonate monooxygenase, the enzyme responsible for the initial oxidation of msa to formaldehyde and sulfite, were cloned and sequenced. they were located on two gene clusters on the chromosome of this bacterium. a 5.0-kbp hindiii fragment contained msma, msmb, and msmc, encoding the large and smal ... | 2002 | 11772638 |
| [search for methanotrophic producers of exopolysaccharides]. | bacteria that produce exopolysaccharides (eps) and use methane as the only source of carbon were selected by studying a collection of methanotroph strains: methylococcus capsulatus e 494, 874, and 3009; m. thermophilus 111p, 112p, and 119p; methylobacter ucrainicus 159 and 161; m. luteus 57v and 12b; methylobacter sp. 100; methylomonas rubra 15 sh and sk-32; methylosinus trichosporium ov3b, ov5b and 4e; m. sporium 5, 12, a20d, and 90v; and methylocystis parvus ovvp. mesophilic methanotroph strai ... | 2001 | 11771325 |
| cytochromes c(550), c(552), and c(1) in the electron transport network of paracoccus denitrificans: redundant or subtly different in function? | paracoccus denitrificans strains with mutations in the genes encoding the cytochrome c(550), c(552), or c(1) and in combinations of these genes were constructed, and their growth characteristics were determined. each mutant was able to grow heterotrophically with succinate as the carbon and free-energy source, although their specific growth rates and maximum cell numbers fell variably behind those of the wild type. maximum cell numbers and rates of growth were also reduced when these strains wer ... | 2001 | 11717258 |
| isolation of bacteria and 16s rdnas from lake vostok accretion ice. | lake vostok, the largest subglacial lake in antarctica, is separated from the surface by approximately 4 km of glacial ice. it has been isolated from direct surface input for at least 420 000 years, and the possibility of a novel environment and ecosystem therefore exists. lake vostok water has not been sampled, but an ice core has been recovered that extends into the ice accreted below glacial ice by freezing of lake vostok water. here, we report the recovery of bacterial isolates belonging to ... | 2001 | 11683867 |
| re-engineering monovalent cation binding sites of methylamine dehydrogenase: effects on spectral properties and gated electron transfer. | methylamine dehydrogenase (madh) is a tryptophan tryptophylquinone (ttq)-dependent enzyme that catalyzes the oxidative deamination of primary amines. monovalent cations are known to affect the spectral properties of madh and to influence the rate of the gated electron transfer (et) reaction from substrate-reduced madh to amicyanin. two putative monovalent cation binding sites in madh have been identified by x-ray crystallography [labesse, g., ferrari, d., chen, z.-w., rossi, g.-l., kuusk, v., mc ... | 2001 | 11591147 |
| pseudo-outbreak of mycobacterium chelonae and methylobacterium mesophilicum caused by contamination of an automated endoscopy washer. | to evaluate an unusual number of rapidly growing acid-fast bacilli, later identified as mycobacterium chelonae, and pink bacteria, later identified as methylobacterium mesophilicum, from fungal cultures obtained by bronchoscopy. | 2001 | 11583208 |
| free energy for blue copper protein unfolding determined by electrospray ionisation mass spectrometry. | an electrospray ionisation (esi) mass spectrometric method for the determination of the free energy (deltag) of unfolding of proteins is described. the method was tested using three blue copper proteins: wild type azurin, cys-3ala/cys-26ala (c3a/c26a) azurin mutant and wild-type amicyanin. the time course of the denaturation process of the proteins dissolved in methanol/water (50:50, v/v, ph 3.5) was followed by recording esi mass spectra at time intervals. the spectra showed two series of peaks ... | 2001 | 11565099 |
| in vitro reconstitution of the myxochelin biosynthetic machinery of stigmatella aurantiaca sg a15: biochemical characterization of a reductive release mechanism from nonribosomal peptide synthetases. | microorganisms produce iron-chelating compounds to sequester the iron essential for growth from the environment. many of these compounds are biosynthesized by nonribosomal peptide synthetases, some in cooperation with polyketide synthases. myxochelins are produced by the myxobacterium stigmatella aurantiaca sg a15, and the corresponding gene cluster was cloned recently. we have undertaken to express heterologously the myxochelin biosynthetic machinery in escherichia coli. to activate the involve ... | 2001 | 11562468 |
| [aerobic methylobacteria are capable of synthesizing auxins]. | obligately and facultatively methylotrophic bacteria with different pathways of c1 metabolism were found to be able to produce auxins, particularly indole-3-acetic acid (iaa), in amounts of 3-100 micrograms/ml. indole-3-pyruvic acid and indole-3-acetamide were detected only in methylobacteria with the serine pathway of c1 metabolism, methylobacterium mesophilicum and aminobacter aminovorans. the production of auxins by methylobacteria was stimulated by the addition of tryptophan to the growth me ... | 2001 | 11558269 |
| [growth of mesophilic methanotrophs at low temperatures]. | the optimal growth of mesophilic methanotrophic bacteria (collection strains of the genera methylocystis, methylomonas, methylosinus, and methylobacter) occurred within temperature ranges of 31-34 degrees c and 23-25 degrees c. none of the strains studied were able to grow at 1.5 or 4 degrees c. representatives of six methanotrophic species (strains mcs. echinoides 2, mm. methanica 12, mb. bovis 89, mcs. pyriformis 14, mb. chroococcum 90, and mb. vinelandii 87) could grow at 10 degrees c (with a ... | 2001 | 11558268 |
| identification of the methylhopanes in sediments and petroleum. | three c31 methylhopanes have been prepared by partial synthesis from appropriate diplopterol precursors. 2 alpha-methyldiplopterol (prepared from 22-hydroxyhopan-3-one), 2 beta-methyldiplopterol (isolated from methylobacterium organophilum), and a mixture of diplopterol and 3 beta-methyldiplopterol (isolated from methylococcus capsulatus) were each converted to the corresponding 17 alpha(h), 21 beta(h)-hopane. comparison of these standards, using gas chromatography--mass spectrometry with mult ... | 1990 | 11537193 |
| characterization of the formyltransferase from methylobacterium extorquens am1. | methylobacterium extorquens am1 possesses a formaldehyde-oxidation pathway that involves enzymes with high sequence identity with enzymes from methanogenic and sulfate-reducing archaea. here we describe the purification and characterization of formylmethanofuran-tetrahydromethanopterin formyltransferase (ftr), which catalyzes the reversible formation of formylmethanofuran (formylmfr) and tetrahydromethanopterin (h4mpt) from n5-formylh4mpt and methanofuran (mfr). formyltransferase from m. extorqu ... | 2001 | 11532013 |
| a direct-method ab initio phasing of a protein, cupredoxin amicyanin, at 1.31 a resolution. | the direct-methods program multan88 has been applied successfully to redetermine the structure of a protein, cupredoxin amicyanin, containing 808 non-h atom sites, one cu atom and 132 ordered water molecules in the asymmetric unit using data at 1.31 a resolution. starting with initially random phases, useful phase sets selected by figures of merit could be obtained from multiple trials. the e maps corresponding to the best eight phase sets in order of combined figures of merit (cfom2) revealed a ... | 2001 | 11526319 |
| structural heterogeneity of blue copper proteins: an epr study of amicyanin and of wild-type and cys3ala/cys26ala mutant azurin. | a comparative investigation of the effects of cooling rate and solvent physicochemical properties on the structural heterogeneity of wild-type and disulfide bond depleted azurin (cys3ala/cys26ala) and of amicyanin has been performed by epr spectroscopy and computer simulation. by describing the spectral features of the epr spectra in terms of gaussian distributions of the components of the g and a tensors of the spin hamiltonian, we have shown that either the cooling rate or the solvent composit ... | 2001 | 11508836 |
| site-directed mutagenesis and x-ray crystallography of the pqq-containing quinoprotein methanol dehydrogenase and its electron acceptor, cytochrome c(l). | two proteins specifically involved in methanol oxidation in the methylotrophic bacterium methylobacterium extorquens have been modified by site-directed mutagenesis. mutation of the proposed active site base (asp303) to glutamate in methanol dehydrogenase (mdh) gave an active enzyme (d303e-mdh) with a greatly reduced affinity for substrate and with a lower activation energy. results of kinetic and deuterium isotope studies showed that the essential mechanism in the mutant protein was unchanged, ... | 2001 | 11502173 |
| development of improved versatile broad-host-range vectors for use in methylotrophs and other gram-negative bacteria. | full exploitation of the information available in bacterial genome sequences requires the availability of facile tools for rapid genetic manipulation. one bacterium for which new genetic tools are needed is the methylotroph methylobacterium extorquens am1. incq and small incp vectors were shown to be unsuitable for use in this bacterium, but a spontaneous mutant of a small incp plasmid was isolated that functioned efficiently in m. extorquens am1. this plasmid was sequenced and used as a base fo ... | 2001 | 11495985 |
| dehalogenation of dichloromethane by dichloromethane dehalogenase/glutathione s-transferase leads to formation of dna adducts. | formation of dna adducts following conversion of dichloromethane by bacterial dichloromethane dehalogenase/glutathione s-transferase was demonstrated. adducts included dichloromethane carbon and glutathione sulfur atoms. a reaction with dna occurred preferentially at guanine bases. increased dna degradation in a pola mutant of methylobacterium dichloromethanicum dm4 grown with dichloromethane confirmed the genotoxicity associated with dichloromethane degradation, suggesting an important role of ... | 2001 | 11489877 |
| a mimic molecule of blue copper protein active site [(-)-sparteine-n,n'](maleonitriledithiolato-s,s')copper(ii). | 2001 | 11487359 | |
| methyl chloride utilising bacteria are ubiquitous in the natural environment. | enrichment and isolation of methyl chloride utilising bacteria from a variety of pristine terrestrial, freshwater, estuarine and marine environments resulted in the detection of six new methyl chloride utilising hyphomicrobium strains, strain cmc related to aminobacter spp. and to two previously isolated methyl halide utilising bacteria cc495 and imb-1, and a gram-positive isolate sac-4 phylogenetically related to nocardioides spp. all the pristine environments sampled for enrichment resulted in ... | 2001 | 11470354 |
| [ nodulation of certain legumes of the genus crotalaria by the new species methylobacterium]. | we studied a collection of 126 rhizobial isolates from eight species of crotalaria (c. comosa, c. glaucoides, c. goreensis, c. hyssopifolia, c. lathyroides, c. perrottetii, c. podocarpa, and c. retusa) growing in senegal. nodulation and nitrogen-fixation tests on nine crotalaria species revealed two specificity groups within the genus crotalaria. group i consists of plants solely nodulated by very specific fast-growing strains. group ii plants are nodulated by slow-growing strains similar to pro ... | 2001 | 11469252 |
| dichloromethane mediated in vivo selection and functional characterization of rat glutathione s-transferase theta 1-1 variants. | methylobacterium dichloromethanicum dm4 is able to grow with dichloromethane as the sole carbon and energy source by using a dichloromethane dehalogenase/glutathione s-transferase (gst) for the conversion of dichloromethane to formaldehyde. mammalian homologs of this bacterial enzyme are also known to catalyze this reaction. however, the dehalogenation of dichloromethane by gst t1-1 from rat was highly mutagenic and toxic to methylotrophic bacteria. plasmid-driven expression of rat gst t1-1 in s ... | 2001 | 11453994 |
| discordant carbapenem susceptibility in methylobacterium species and its application as a method for phenotypic identification. | 2001 | 11388170 | |
| [processes of plant colonization by methylobacterium strains and some bacterial properties ]. | the pink-pigmented facultative methylotrophic bacteria (ppfmb) of the genus methylobacterium are indespensible inhabitants of the plant phyllosphere. using maize zea mays as a model, the ways of plant colonization by ppfmb and some properties of the latter that might be beneficial to plants were studied. a marked strain, methylobacterium mesophilicum apr-8 (pulb113), was generated to facilitate the detection of the methylotrophic bacteria inoculated into the soil or applied to the maize leaves. ... | 2001 | 11386061 |
| molecular characterization of a blue-copper laccase, tila, of aspergillus nidulans. | laccases are blue-copper enzymes, which oxidize phenolic substrates and thereby reduce molecular oxygen. they are widespread within fungi and are involved in lignin degradation or secondary metabolism such as pigment biosynthesis. many fungi contain several laccases, not all of whose functions are known. in aspergillus nidulans one, ya, is expressed during asexual development and converts a yellow precursor to the green pigment. we identified a second laccase gene, which encodes a 66.3-kda prote ... | 2001 | 11377869 |
| chloromethane: tetrahydrofolate methyl transfer by two proteins from methylobacterium chloromethanicum strain cm4. | the cmua and cmub genes are required for growth of methylobacterium chloromethanicum strain cm4 with chloromethane as the sole carbon source. while cmub was previously shown to possess methylcobalamin:tetrahydrofolate methyltransferase activity, sequence analysis indicated that cmua represented a novel and so far unique two-domain methyltransferase/corrinoid-binding protein involved in methyl transfer from chloromethane to a corrin moiety. cmua was purified from wild-type m. chloromethanicum str ... | 2001 | 11358510 |
| crystal structure of a novel red copper protein from nitrosomonas europaea. | nitrosocyanin (nc) is a mononuclear red copper protein isolated from the ammonia oxidizing bacterium nitrosomonas europaea. although nc exhibits some sequence homology to classic blue copper proteins, its spectroscopic and electrochemical properties are drastically different. the 1.65 a resolution crystal structure of oxidized nc reveals an unprecedented trimer of single domain cupredoxins. each copper center is partially covered by an unusual extended beta-hairpin structure from an adjacent mon ... | 2001 | 11341832 |
| [phylogenetic analysis of aerobic methylotrophic bacteria, using dichloromethane]. | the phylogenetic relationships of 12 aerobic dichloromethane-degrading bacteria that implement different c1-assimilation pathways was determined based on 16s ribosomal rna sequences and dna-dna hybridization data. the restricted facultative methylotroph "methylophilus leisingerii" dm11 with the ribulose monophosphate pathway was found to belong to the genus methylophilus cluster of the beta subdivision of the phylogenetic kingdom proteobacteria. the facultative methylotroph methylorhabdus multiv ... | 2001 | 11338843 |
| determination of the electron self-exchange rates of blue copper proteins by super-weft nmr spectroscopy. | an nmr approach for determining the electron self-exchange (ese) rate constants in blue copper proteins is presented. the approach uses the paramagnetic relaxation enhancement of resonances in 1d 1h super-weft spectra of partly oxidized (paramagnetic) proteins. these spectra allow a more precise determination of the relevant paramagnetic linebroadenings than conventional 1d 1h spectra and, thus, permit a more detailed investigation of the applicability of the linebroadenings for determining the ... | 2001 | 11330808 |
| [methylovorus mays--novel species of aerobic, obligatory methylotrophic bacteria associated with plants]. | a bacterial strain utilizing methanol as the sole source of carbon and energy was isolated from the maize phyllosphere. cells are nonpigmented gram-negative motile rods that do not form spores or prosthecae and reproduce by binary fission. the strain does not require vitamins or supplementary growth factors. it is obligately aerobic and urease-, oxidase-, and catalase-positive. the optimum growth temperature is 35-40 degrees c; the optimum ph is 7.0-7.5. the doubling time is 2 h. the bacterium i ... | 2000 | 11315676 |
| variability and interactions between endophytic bacteria and fungi isolated from leaf tissues of citrus rootstocks. | fungi and bacteria were isolated from surface disinfected leaf tissues of several citrus rootstocks. the principal bacterial species isolated were alcaligenes sp., bacillus spp. (including b. cereus, b. lentus, b. megaterium, b. pumilus, and b. subtilis), burkholderia cepacia, curtobacterium flaccumfaciens, enterobacter cloacae, methylobacterium extorquens, and pantoea agglomerans, with p. agglomerans and b. pumilus being the most frequently isolated species. the most abundant fungal species wer ... | 2001 | 11315114 |
| [unique properties of highly radioresistant bacteria]. | in connection with the chernobyl nuclear power plant (chnpp) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. the analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. the extreme radioresistant bacteria are represented ... | 2000 | 11300085 |
| re-face stereospecificity of nadp dependent methylenetetrahydromethanopterin dehydrogenase from methylobacterium extorquens am1 as determined by nmr spectroscopy. | mtda catalyzes the dehydrogenation of n(5),n(10)-methylenetetrahydromethanopterin (methylene-h4mpt) with nadp(+) as electron acceptor. in the reaction two prochiral centers are involved, c14a of methylene-h4mpt and c4 of nadp(+), between which a hydride is transferred. the two diastereotopic protons at c14a of methylene-h4mpt and at c4 of nadph can be seen separately in 1h-nmr spectra. this fact was used to determine the stereospecificity of the enzyme. with (14ar)-[14a-2h(1)]-[14a-13c]methylene ... | 2001 | 11297742 |
| identification of methyl halide-utilizing genes in the methyl bromide-utilizing bacterial strain imb-1 suggests a high degree of conservation of methyl halide-specific genes in gram-negative bacteria. | strain imb-1, an aerobic methylotrophic member of the alpha subgroup of the proteobacteria, can grow with methyl bromide as a sole carbon and energy source. a single cmu gene cluster was identified in imb-1 that contained six open reading frames: cmuc, cmua, orf146, paae, huti, and partial metf. cmua from imb-1 has high sequence homology to the methyltransferase cmua from methylobacterium chloromethanicum and hyphomicrobium chloromethanicum and contains a c-terminal corrinoid-binding motif and a ... | 2001 | 11282657 |
| sequence variation in dichloromethane dehalogenases/glutathione s-transferases. | dichloromethane dehalogenase/glutathione s-transferase allows methylotrophic bacteria to grow with dichloromethane (dcm), a predominantly man-made compound. bacteria growing with dcm by virtue of this enzyme have been readily isolated in the past. so far, the sequence of the dcma gene encoding dcm dehalogenase has been determined for methylobacterium dichloromethanicum dm4 and methylophilus sp. dm11. dcm dehalogenase genes closely related to that of strain dm4 were amplified by pcr and cloned fr ... | 2001 | 11238968 |
| mimicking biological electron transfer and oxygen activation involving iron and copper proteins: a bio(in)organic supramolecular approach. | 2001 | 11219019 | |
| hyphomicrobium chloromethanicum sp. nov. and methylobacterium chloromethanicum sp. nov., chloromethane-utilizing bacteria isolated from a polluted environment. | two chloromethane-utilizing facultatively methylotrophic bacteria, strains cm2t and cm4t, were isolated from soil at a petrochemical factory. on the basis of their morphological, physiological and genotypical properties, strain cm2t (= vkm b-2176t = ncimb 13687t) is proposed as a new species of the genus hyphomicrobium, hyphomicrobium chloromethanicum, and strain cm4t (= vkm b-2223t = ncimb 13688t) as a new species of the genus methylobacterium, methylobacterium chloromethanicum. | 2001 | 11211248 |
| connection between poly-beta-hydroxybutyrate biosynthesis and growth on c(1) and c(2) compounds in the methylotroph methylobacterium extorquens am1. | several dna regions containing genes involved in poly-beta-hydroxybutyrate (phb) biosynthesis and degradation and also in fatty acid degradation were identified from genomic sequence data and have been characterized in the serine cycle facultative methylotroph methylobacterium extorquens am1. genes involved in phb biosynthesis include those encoding beta-ketothiolase (phaa), nadph-linked acetoacetyl coenzyme a (acetyl-coa) reductase (phab), and phb synthase (phac). phaa and phab are closely link ... | 2001 | 11208803 |
| the effect of ph and ligand exchange on the redox properties of blue copper proteins. | a study of the structure and redox properties of the copper site in azurins by means of exafs, nmr, redox titrations, potentiometry, equilibrium cyclic voltammetry and rapid scan voltammetry on protein films is reported. the results are discussed in light of existing theories on structure and function of type-1 copper sites. the exit and entry of electrons take place through the c-terminal histidine ligand of the copper. the hydrophobic patch through which this residue penetrates the protein sur ... | 2000 | 11197479 |
| effects of ca2+ on the activity and stability of methanol dehydrogenase. | the effects of exogenously added ca2+ on the enzymatic activity and structural stability of methanol dehydrogenase were studied for various ca2+ concentrations. methanol dehydrogenase activity increased significantly with increasing concentration of ca2+, approaching saturation at 200 mm ca2+. the effect of ca2+ on the activation of mdh was time dependent and ca2+ specific and was due to binding of the metal ions to the enzyme. addition of increasing concentration of ca2+ caused a decrease of th ... | 2000 | 11195971 |
| [facultative and obligate aerobic methylobacteria synthesize cytokinins]. | the presence and expression of genes controlling the synthesis and secretion of cytokinins by the pink-pigmented facultative methylotroph methylobacterium mesophilicum vkm b-2143 with the serine pathway and nonpigmented obligate methylotroph methylovorus mays vkm b-2221 with the ribulose monophosphate pathway of c1 metabolism were shown using the polymerase chain reaction (pcr) and reverse transcription-pcr methods. the presence of the corresponding mrna in m. mesophilicum cells grown on methano ... | 2000 | 11195573 |
| methylamine dehydrogenase. structure and function of electron transfer complexes. | 2000 | 11192720 | |
| an amicyanin c-terminal loop mutant where the active-site histidine donor cannot be protonated. | a novel blue copper protein was constructed by replacing the c-terminal loop of amicyanin (paracoccus versutus) by the homologous loop of rusticyanin. the c-terminal loop of both amicyanin and rusticyanin contains three (his, cys, met) of the four copper ligands. the amicyanin mutant exhibits all spectroscopic properties normally encountered for blue copper sites. the midpoint potential (369 mv) is the highest reported value for an amicyanin mutant. cyclic voltammetry and nmr studies of the redu ... | 2001 | 11191220 |
| monitoring for methylobacteria in water systems. | 2000 | 11185064 | |
| crystal structure of auracyanin, a "blue" copper protein from the green thermophilic photosynthetic bacterium chloroflexus aurantiacus. | auracyanin b, one of two similar blue copper proteins produced by the thermophilic green non-sulfur photosynthetic bacterium chloroflexus aurantiacus, crystallizes in space group p6(4)22 (a=b=115.7 a, c=54.6 a). the structure was solved using multiple wavelength anomalous dispersion data recorded about the cuk absorption edge, and was refined at 1.55 a resolution. the molecular model comprises 139 amino acid residues, one cu, 247 h(2)o molecules, one cl(-) and two so(4)(2-). the final residual a ... | 2001 | 11178893 |
| electronic characterization of the oxidized state of the blue copper protein rusticyanin by 1h nmr: is the axial methionine the dominant influence for the high redox potential? | the oxidized state of rusticyanin, the blue copper protein with the highest redox potential in its class, has been investigated through (1)h nuclear magnetic resonance applied to its cobalt(ii) derivative. the assignment of the protons belonging to the coordinated residues has been performed. many other amino acids situated in the vicinity of the metal ion, including six hydrophobic residues (isoleucine140 and five phenylalanines) have also been identified. the orientation of the main axes of th ... | 2001 | 11170402 |
| new pathway of amine oxidation respiratory chain of paracoccus denitrificans ifo 12442. | the physiological electron acceptor of quinohemoprotein amine dehydrogenase (qh-amdh) from paracoccus denitrificans ifo 12442 was identified by biochemical and electrochemical methods. of three types of heme c-containing proteins purified together with qh-amdh from the periplasm of n-butylamine-grown cells, only constitutive cytochrome c-550 was reduced by the addition of qh-amdh and n-butylamine. reconstitution of the respiratory chain revealed that cytochrome c-550 mediates the electron transf ... | 2001 | 11168384 |
| chloromethane utilization gene cluster from hyphomicrobium chloromethanicum strain cm2(t) and development of functional gene probes to detect halomethane-degrading bacteria. | hyphomicrobium chloromethanicum cm2(t), an aerobic methylotrophic member of the alpha subclass of the class proteobacteria, can grow with chloromethane as the sole carbon and energy source. h. chloromethanicum possesses an inducible enzyme system for utilization of chloromethane, in which two polypeptides (67-kda cmua and 35-kda cmub) are expressed. previously, four genes, cmua, cmub, cmuc, and puru, were shown to be essential for growth of methylobacterium chloromethanicum on chloromethane. the ... | 2001 | 11133460 |
| methylotrophic methylobacterium bacteria nodulate and fix nitrogen in symbiosis with legumes. | rhizobia described so far belong to three distinct phylogenetic branches within the alpha-2 subclass of proteobacteria. here we report the discovery of a fourth rhizobial branch involving bacteria of the methylobacterium genus. rhizobia isolated from crotalaria legumes were assigned to a new species, "methylobacterium nodulans," within the methylobacterium genus on the basis of 16s ribosomal dna analyses. we demonstrated that these rhizobia facultatively grow on methanol, which is a characterist ... | 2001 | 11114919 |
| production of green fluorescent protein by the methylotrophic bacterium methylobacterium extorquens. | the production of green fluorescent protein (gfp) in methylobacterium extorquens was studied by creating four different constructs using pjb3kmd, prk310 and pvk101 vectors, as well as plac and soluble methane monooxygenase (smmo) promoters. plasmids were introduced into the cells by electroporation. expression of gfp by selected clones was evaluated by growing cells in complex or defined media. the use of prk310 as an expression vector containing the lacz promoter resulted in a 100-fold increase ... | 2000 | 11111023 |
| divergent mechanisms of 5' 23s rrna ivs processing in the alpha-proteobacteria. | widespread occurrence of a separate small rna derived from the 5'-end of 23s rrna and of an intervening sequence (ivs) which separates this domain from the main segment of 23s rrna in the alpha-proteobacteria implies that processing reactions which act to excise the ivs are also maintained in this group. we previously characterized the first example of processing of this ivs in rhodopseudomonas palustris, which is classified with the bradyrhizobia in this case, ivs excision occurs by a multistep ... | 2000 | 11095671 |
| on the role of strain in blue copper proteins. | theoretical investigations of the structure and function of the blue copper proteins are described. we have studied the optimum vacuum geometry of oxidised and reduced copper sites, the relative stability of trigonal and tetragonal cu(ii) structures, the relation between the structure and electronic spectra, the reorganisation energy, and reduction potentials. our calculations give no support to the suggestion that strain plays a significant role in the function of these proteins; on the contrar ... | 2000 | 11085647 |
| energy saving electron pathways in proteins. | this paper is a contribution to the discussion of whether the general architecture of electron transfer sites in blue copper proteins is mainly a result of the structural preferences of the metal ion or is induced by the protein. although the site is probably stable only when protected by the protein, there appears to be no strain from the latter on the structure in the vicinity of the copper atom. for an operative redox site it is further required that the geometry of the site is acceptable for ... | 2000 | 11085646 |
| copper coordination in blue proteins. | the spectroscopic and electrochemical properties of blue copper proteins are strikingly different from those of inorganic copper complexes in aqueous solution. over three decades ago this unusual behavior was ascribed to constrained coordination in the folded protein; consistent with this view, crystal structure determinations of blue proteins have demonstrated that the ligand positions are essentially unchanged on reduction as well as in the apoprotein. blue copper reduction potentials are tune ... | 2000 | 11085645 |
| novel formaldehyde-activating enzyme in methylobacterium extorquens am1 required for growth on methanol. | formaldehyde is toxic for all organisms from bacteria to humans due to its reactivity with biological macromolecules. organisms that grow aerobically on single-carbon compounds such as methanol and methane face a special challenge in this regard because formaldehyde is a central metabolic intermediate during methylotrophic growth. in the alpha-proteobacterium methylobacterium extorquens am1, we found a previously unknown enzyme that efficiently catalyzes the removal of formaldehyde: it catalyzes ... | 2000 | 11073907 |
| methylarcula marina gen. nov., sp. nov. and methylarcula terricola sp. nov.: novel aerobic, moderately halophilic, facultatively methylotrophic bacteria from coastal saline environments. | a new genus, methylarcula, with two new species, methylarcula marina and methylarcula terricola, are proposed for strains h1t and h37t of moderately halophilic facultatively methylotrophic bacteria isolated from the coastal saline habitats. these methylobacteria are aerobic, gram-negative, asporogenous, non-motile, colourless rods that multiply by binary fission. their cellular fatty acids profiles consist primarily of straight-chain unsaturated (c18:1; 70-80%), saturated (c18:0; 14-16%) and cyc ... | 2000 | 11034496 |
| dna polymerase i is essential for growth of methylobacterium dichloromethanicum dm4 with dichloromethane. | methylobacterium dichloromethanicum dm4 grows with dichloromethane as the unique carbon and energy source by virtue of a single enzyme, dichloromethane dehalogenase-glutathione s-transferase. a mutant of the dichloromethane-degrading strain m. dichloromethanicum dm4, strain dm4-1445, was obtained by mini-tn5 transposon mutagenesis that was no longer able to grow with dichloromethane. dichloromethane dehalogenase activity in this mutant was comparable to that of the wild-type strain. the site of ... | 2000 | 10986246 |
| blue copper proteins: a comparative analysis of their molecular interaction properties. | blue copper proteins are type-i copper-containing redox proteins whose role is to shuttle electrons from an electron donor to an electron acceptor in bacteria and plants. a large amount of experimental data is available on blue copper proteins; however, their functional characterization is hindered by the complexity of redox processes in biological systems. we describe here the application of a semiquantitative method based on a comparative analysis of molecular interaction fields to gain insigh ... | 2000 | 10975566 |
| methylopila helvetica sp. nov. and methylobacterium dichloromethanicum sp. nov.--novel aerobic facultatively methylotrophic bacteria utilizing dichloromethane. | eight strains of gram-negative, aerobic, asporogenous, neutrophilic, mesophilic, facultatively methylotrophic bacteria are taxonomically described. these icl- serine pathway methylobacteria utilize dichloromethane, methanol and methylamine as well as a variety of polycarbon compounds as the carbon and energy source. the major cellular fatty acids of the non-pigmented strains dm1, dm3, and dm5 to dm9 are c18:1, c16:0, c18:0, ccy19:0 and that of the pink-pigmented strain dm4 is c18:1. the main qui ... | 2000 | 10930073 |
| the met99gln mutant of amicyanin from paracoccus versutus. | the axial copper ligand methionine has been replaced by a glutamine in the cupredoxin amicyanin from paracoccus versutus. dynamic and structural characteristics of the mutant have been studied in detail using uv/vis, epr, nmr, cyclic voltammetry, and isomorphous metal replacement. m99q amicyanin is a blue copper protein with significant spectral and structural similarities to the other cupredoxins umecyanin, stellacyanin, and m121q azurin. in addition, the functional properties of m99q amicyanin ... | 2000 | 10924152 |
| volatile organic compounds associated with microbial growth in automobile air conditioning systems. | volatile organic compounds from penicillium viridicatum and methylobacterium mesophilicum growing on laboratory media and on component materials of automobile air conditioners were analyzed with gas chromatography and mass spectrometry. p. viridicatum produced compounds such as 4-methyl thiazole, terpenes and alcohols, whereas m. mesophilicum produced dimethyl disulfide, dimethyl trisulfide, and chlorophenol with growth on laboratory media. in comparison with laboratory media, fewer volatiles we ... | 2000 | 10915209 |
| molecular basis for complex formation between methylamine dehydrogenase and amicyanin revealed by inverse mutagenesis of an interprotein salt bridge. | methylamine dehydrogenase (madh) and amicyanin form a physiologic complex which is required for interprotein electron transfer. the crystal structure of this protein complex is known, and the importance of certain residues on amicyanin in its interaction with madh has been demonstrated by site-directed mutagenesis. in this study, site-directed mutagenesis of madh, kinetic data, and thermodynamic analysis are used to probe the molecular basis for stabilization of the protein complex by an interpr ... | 2000 | 10913294 |
| diversity of culturable heterotrophic aerobic bacteria in pristine stream bed sediments. | more than 900 culturable, heterotrophic aerobic isolates were obtained from the sediments of a forested, pristine stream and analyzed using three classical microbiological tests: api 20e, amplified ribosomal dna restriction analysis (ardra), and fatty acid analysis. gram-negative bacteria comprised most of the heterotrophic aerobic isolates (66.7%), similar to other oligotrophic environments. the isolates were assigned to the genus level as pseudomonas, flavobacterium, micrococcus, bacillus, chr ... | 1999 | 10907425 |
| methylobacterium mesophilicum infection: case report and literature review of an unusual opportunistic pathogen. | methylobacterium mesophilicum is a methylotrophic, pink pigmented, gram-negative rod that was initially isolated from environmental sources that is being increasingly reported as a cause of opportunistic infections in immunocompromised hosts. we present the case of an immunocompromised woman who developed a central catheter infection with m. mesophilicum and review the other 29 cases reported in the literature, noting that it is frequently resistant to beta-lactam agents but is generally suscept ... | 2000 | 10880304 |
| detection of intracellular bacteria in the buds of scotch pine (pinus sylvestris l.) by in situ hybridization. | bacterial isolates were obtained from pine (pinus sylvestris l.) tissue cultures and identified as methylobacterium extorquens and pseudomonas synxantha. the existence of bacteria in pine buds was investigated by 16s rrna in situ hybridization. bacteria inhabited the buds of every tree examined, primarily colonizing the cells of scale primordia and resin ducts. | 2000 | 10877808 |
| characterization of a second methylene tetrahydromethanopterin dehydrogenase from methylobacterium extorquens am1. | cell extracts of methylobacterium extorquens am1 were recently found to catalyze the dehydrogenation of methylene tetrahydromethanopterin (methylene h4mpt) with nad+ and nadp+. the purification of a 32-kda nadp-specific methylene h4mpt dehydrogenase (mtda) was described already. here we report on the characterization of a second methylene h4mpt dehydrogenase (mtdb) from this aerobic alpha-proteobacterium. purified mtdb with an apparent molecular mass of 32 kda was shown to catalyze the oxidation ... | 2000 | 10848995 |
| detection and classification of atmospheric methane oxidizing bacteria in soil. | well-drained non-agricultural soils mediate the oxidation of methane directly from the atmosphere, contributing 5 to 10% towards the global methane sink. studies of methane oxidation kinetics in soil infer the activity of two methanotrophic populations: one that is only active at high methane concentrations (low affinity) and another that tolerates atmospheric levels of methane (high affinity). the activity of the latter has not been demonstrated by cultured laboratory strains of methanotrophs, ... | 2000 | 10821271 |
| isolation and characterization of two new methanesulfonic acid-degrading bacterial isolates from a portuguese soil sample. | two novel bacterial strains that can utilize methanesulfonic acid as a source of carbon and energy were isolated from a soil sample collected in northern portugal. morphological, physiological, biochemical and molecular biological characterization of the two isolates indicate that strain p1 is a pink-pigmented facultative methylotroph belonging to the genus methylobacterium, while strain p2 is a restricted methylotroph belonging to the genus hyphomicrobium. both strains are strictly aerobic, deg ... | 2000 | 10795686 |
| molecular analyses of novel methanotrophic communities in forest soil that oxidize atmospheric methane. | forest and other upland soils are important sinks for atmospheric ch(4), consuming 20 to 60 tg of ch(4) per year. consumption of atmospheric ch(4) by soil is a microbiological process. however, little is known about the methanotrophic bacterial community in forest soils. we measured vertical profiles of atmospheric ch(4) oxidation rates in a german forest soil and characterized the methanotrophic populations by pcr and denaturing gradient gel electrophoresis (dgge) with primer sets targeting the ... | 2000 | 10788342 |
| electronic structure contributions to electron transfer in blue cu and cu(a). | the experimentally determined electronic structures of mononuclear blue cu and binuclear cu(a) centers are summarized and their relation to intra- and inter-protein electron transfer (et) kinetics are described. specific contributions of the electronic structures of these two broad classes of cu et proteins to h(ab), lambda, and deltae degrees are discussed. also, the role of the protein structure in determining key geometric features which define the electronic structures of the metal sites in ... | 2000 | 10766432 |
| x-ray structure of the quinoprotein ethanol dehydrogenase from pseudomonas aeruginosa: basis of substrate specificity. | the homodimeric enzyme form of quinoprotein ethanol dehydrogenase from pseudomonas aeruginosa atcc 17933 crystallizes readily with the space group r3. the x-ray structure was solved at 2.6 a resolution by molecular replacement. aside from differences in some loops, the folding of the enzyme is very similar to the large subunit of the quinoprotein methanol dehydrogenases from methylobacterium extorquens or methylophilus w3a1. eight w-shaped beta-sheet motifs are arranged circularly in a propeller ... | 2000 | 10736230 |
| structure, function, and applications of tryptophan tryptophylquinone enzymes. | tryptophan and tyrosine residues in proteins may be posttranslationally modified to form enzyme cofactors. tryptophan tryptophylquinone (ttq), the cofactor of methylamine dehydrogenase (madh), is formed by covalent cross-linking of two tryptophan residues and incorporation of two oxygen atoms into one of the indole rings to form a quinone. madh converts primary amines to their corresponding aldehydes plus ammonia. during the catalytic cycle, ttq mediates electron transfer from substrate to a cop ... | 1999 | 10721104 |
| tyr(30) of amicyanin is not critical for electron transfer to cytochrome c-551i: implications for predicting electron transfer pathways. | a pathways analysis of the methylamine dehydrogenase-amicyanin-cytochrome c-551i protein electron transfer (et) complex predicts two sets of et pathways of comparable efficiency from the type i copper of amicyanin to the heme of cytochrome c-551i. in one pathway, the electron exits copper via the cys(92) copper ligand, and in the other, it exits via the met(98) copper ligand. if the pathways algorithm is modified to include contributions from the anisotropy of metal-ligand coupling, independent ... | 2000 | 10692547 |
| analysis of two formaldehyde oxidation pathways in methylobacillus flagellatus kt, a ribulose monophosphate cycle methylotroph. | the roles of cyclic formaldehyde oxidation via 6-phosphogluconate dehydrogenase and linear oxidation via the tetrahydromethanopterin (h4mpt)-linked pathway were assessed in an obligate methylotroph, methylobacillus flagellatus kt, by cloning, sequencing and mutating two chromosomal regions containing genes encoding enzymes specifically involved in these pathways: 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase and methenyl h4mpt cyclohydrolase (gnda, zwf and mch). no null mut ... | 2000 | 10658669 |
| culture-dependent and culture-independent characterization of microbial assemblages associated with high-temperature petroleum reservoirs. | recent investigations of oil reservoirs in a variety of locales have indicated that these habitats may harbor active thermophilic prokaryotic assemblages. in this study, we used both molecular and culture-based methods to characterize prokaryotic consortia associated with high-temperature, sulfur-rich oil reservoirs in california. enrichment cultures designed for anaerobic thermophiles, both autotrophic and heterotrophic, were successful at temperatures ranging from 60 to 90 degrees c. heterotro ... | 2000 | 10653739 |
| spectroscopic and electrochemical properties of two azurins (az-iso1 and az-iso2) from the obligate methylotroph methylomonas sp. strain j and the structure of novel az-iso2. | two azurin-type blue copper proteins, which are related to the electron-transfer processes involving methylamine/methanol oxidation, have been spectroscopically and electrochemically characterized. the obligate methylotroph methylomonas sp. strain j gives rise to two azurins (az-isol and az-iso2) with methylamine dehydrogenase (madh-mj). the intense blue bands characteristic of az-iso1 and az-iso2 are observed at 621 and 616 nm in the visible absorption spectra respectively, being revealed at 62 ... | 1999 | 10631606 |
| microbial metabolism of methanesulfonic acid | methanesulfonic acid is a very stable strong acid and a key intermediate in the biogeochemical cycling of sulfur. it is formed in megatonne quantities in the atmosphere from the chemical oxidation of atmospheric dimethyl sulfide (most of which is of biogenic origin) and deposited on the earth in rain and snow, and by dry deposition. methanesulfonate is used by diverse aerobic bacteria as a source of sulfur for growth, but is not known to be used by anaerobes either as a sulfur source, a fermenta ... | 1999 | 10591843 |