Publications

structural aspects of the dye-linked alcohol dehydrogenase of rhodopseudomonas acidophila.	1. a dye-linked alcohol dehydrogenase was purified 60-fold from extracts of rhodopseudomonas acidophila 10050 grown aerobically on ethanol. 2. the properties of this enzyme were identical with those of the alcohol dehydrogenase synthesized by this organism during growth on methanol anaerobically in the light, and they are judged to be the same enzyme. 3. the enzyme gave a single protein band, coincident with alcohol dehydrogenase activity, during electrophoresis on polyacrylamide gel. 4. the ami ...	1979	229820
the interaction of methanol dehydrogenase and its electron acceptor, cytochrome cl in methylotrophic bacteria.	the interactions of methanol dehydrogenase (mdh, ec1.1.99.8) with its specific electron acceptor cytochrome cl has been investigated in methylobacterium extorquens and methylophilus methylotrophus. the mdhs of these two very different methylotrophs have the same alpha 2 beta 2 structure; the interaction of these mdhs with their specific electron acceptor, cytochrome cl, has been studied using a novel assay system. electrostatic reactions are involved in 'docking' of the two proteins. edta inhibi ...	1992	1311606
involvement of a labile axial histidine in coupling electron and proton transfer in methylophilus methylotrophus cytochrome c''.	methylophilus methylotrophus cytochrome c'' is an unusual monohaem protein (15 kda) undergoing a redox-linked spin-state transition [santos, h. & turner, d. l. (1988) biochim. biophys. acta 954, 277-286]. the midpoint redox potential of cytochrome c" was measured over the ph range 4-10. the ph dependence of the midpoint redox potential was interpreted in terms of a model that considers the redox-state dependence of the ionization of two distinct and non-interacting protonated groups in the prote ...	1992	1325909
the three-dimensional structures of methanol dehydrogenase from two methylotrophic bacteria at 2.6-a resolution.	the structures of methanol dehydrogenase (medh) from two closely related methylotrophic bacteria, methylophilus methylotrophus and w3a1, have been determined at 2.6-a resolution. the molecule, a quinoprotein of molecular mass of about 138 kda, contains two heavy (h) and two light (l) subunits of unknown sequence and two molecules of noncovalently associated pyrroloquinoline quinone. the two enzymes crystallize isomorphously in space group p2(1) with one h2l2 heterotetramer in the asymmetric unit ...	1992	1331050
characterization of mutant forms of the quinoprotein methanol dehydrogenase lacking an essential calcium ion.	methanol dehydrogenase (mdh) from methylobacterium extorquens, methylophilus methylotrophus, paracoccus denitrificans and hyphomicrobium x all contained a single atom of ca2+ per alpha 2 beta 2 tetramer. the role of ca2+ was investigated using the mdh from methylobacterium extorquens. this was shown to be similar to the mdh from hyphomicrobium x in having 2 mol of prosthetic group (pyrroloquinoline quinine; pqq) per mol of tetramer, the pqq being predominantly in the semiquinone form. mdh isolat ...	1992	1332681
preparation of isotopically labeled ribonucleotides for multidimensional nmr spectroscopy of rna.	a general method for large scale preparation of uniformly isotopically labeled ribonucleotides and rnas is described. bacteria are grown on isotopic growth medium, and their nucleic acids are harvested and degraded to mononucleotides. these are enzymatically converted into ribonucleoside triphosphates, which are used in transcription reactions in vitro to prepare rnas for nmr studies. for 15n-labeling, e.coli is grown on 15n-ammonium sulfate, whereas for 13c-labeling, methylophilus methylotrophu ...	1992	1383928
the periplasmic modifier protein for methanol dehydrogenase in the methylotrophs methylophilus methylotrophus and paracoccus denitrificans.	a modifier protein (m-protein), which increases the affinity of methanol dehydrogenase (mdh) for alcohols but decreases its affinity for formaldehyde, has been partially purified from methylophilus methylotrophus and paracoccus denitrificans. analysis was complicated by non-protein factors in bacterial extracts that are able to mimic m-protein in one of its functions-that of increasing the activity of mdh with butane-1,3-diol in the dye-linked assay system. the 67 kda polypeptide, previously ide ...	1991	1663153
16s ribosomal rna sequence analysis for determination of phylogenetic relationship among methylotrophs.	16s ribosomal rnas (rrna) of 12 methylotrophic bacteria have been almost completely sequenced to establish their phylogenetic relationships. methylotrophs that are physiologically related are phylogenetically diverse and are scattered among the purple eubacteria (class proteobacteria). group i methylotrophs can be classified in the beta- and the gamma-subdivisions and group ii methylotrophs in the alpha-subdivision of the purple eubacteria, respectively. pink-pigmented facultative and non-pigmen ...	1990	1693657
electron-transfer flavoproteins from methylophilus methylotrophus and bacterium w3a1.		1990	2126331
cytochrome c'' isolated from methylophilus methylotrophus. an example of bis-histidine-co-ordinated fe3+ haem, with near-perpendicular orientation of the ligands.	cytochrome c'' (methylophilus methylotrophus) is a soluble protein, mr 15,000, possessing one haem which is high-spin in the reduced state but switches to a low-spin form on oxidation. low-temperature electron-paramagnetic-resonance spectroscopy of the oxidized state shows a low-spin signal at gz = 3.65 with a folded line-shape typical of a haem of low rhombicity, and the near-infrared magnetic-circular-dichroism (m.c.d.) spectra reveal an unusually intense (delta epsilon = 400 m-1.cm-1 at 5 t, ...	1990	2169241
[analysis of dna-dna homologies in obligate methylotrophic bacteria].	the genotypic affinity of 19 bacterial strains obligately dependent on methanol or methylamine as carbon and energy sources was studied by techniques of molecular dna hybridization. the high homology level (35-88%) between motile strain methylophilus methanolovorus v-1447d and nonmotile strain methylobacillus sp. vsb-792 as well as other motile strains (pseudomonas methanolica atcc 21704, methylomonas methanolica nrrl 5458, pseudomonas sp. w6, strain a3) indicates that all of them belong to one ...	1988	2463459
studies on electron transfer from methanol dehydrogenase to cytochrome cl, both purified from hyphomicrobium x.	ferricytochrome cl isolated from hyphomicrobium x is an electron acceptor in assays for homologous methanol dehydrogenase (mdh), albeit a poor one compared with artificial dyes. the intermediates of mdh seen during the reaction are identical with those observed with wurster's blue as electron acceptor, indicating that the reaction cycles are similar. the assay showed a ph optimum of approx. 7.0 and scarcely any stimulation by nh4cl, this being in contrast with assays with artificial dyes, where ...	1989	2537627
unusual redox properties of electron-transfer flavoprotein from methylophilus methylotrophus.	the most positive redox potential ever recorded for a flavin adenine dinucleotide (fad) containing protein has been measured for an electron-transfer flavoprotein (etf) synthesized by methylophilus methylotrophus. this potential value, 0.196 v versus the standard hydrogen electrode (vs she), was measured at ph 7.0 for the one-electron reduction of fully oxidized etf (etfox) to the red anionic semiquinone form of etf (etf.-). quantitative formation of etf.- was observed. the first successful redu ...	1989	2605209
isolation and computer-aided characterization of mmei, a type ii restriction endonuclease from methylophilus methylotrophus.	a type ii restriction endonuclease, mmei, has been purified from the obligate methylotroph, methylophilus methylotrophus. the enzyme was shown to have the non-palindromic recognition sequence 5'-t c c pu a c (n)20-3', 3'-a g g py t g (n)18-5' and to cleave (as indicated) on the 3' side, generating a two nucleotide 3' projection. determination of the recognition sequence was achieved using two new computer programs; recog, which predicts recognition sequences from the pattern of restriction fragm ...	1986	3016643
molecular cloning of a reca-like gene of methylophilus methylotrophus and identification of its product.	a recombinant plasmid, ppf5, has been constructed which contains a 5.5-kb fragment of methylophilus methylotrophus dna inserted into pat153, and which confers resistance to uv and mitomycin c (mc) upon escherichia coli reca mutants. hybridisation analysis indicates that sequence homology exists between the cloned dna and a fragment of e. coli chromosomal dna that contains the reca gene. tn1000 insertions have been isolated within ppf5 that inactivate its ability to complement reca mutations, and ...	1986	3021589
the apparent oxidation of nadh by whole cells of the methylotrophic bacterium methylophilus methylotrophus. a cautionary tale.	previous reports that whole cells of methylophilus methylotrophus oxidase exogenous nadh have been investigated. essentially identical rates of oxygen consumption were observed following the addition of methanol or nadh to whole cells. both activities were inhibited by edta and hydroxylamine, but not by hqno, and exhibited similar ph optima. analyses of the reaction stoichiometry with nadh as substrate showed that the expected amount of oxygen was consumed, but also revealed acidification (inste ...	1986	3098164
preliminary x-ray crystallographic study of methanol dehydrogenase from methylophilus methylotrophus.	single crystals of methanol dehydrogenase from methylophilus methylotrophus have been prepared by the macroseeding method. the crystals belong to the monoclinic space group c2, and have unit cell parameters a = 125.62 a, b = 63.83 a, c = 83.99 a, and beta = 93.24 degrees. there is one 62,000 mr monomer in the asymmetric unit. the crystals diffract to beyond 2.0 a resolution.	1986	3098983
transfer of plasmids from escherichia coli and pseudomonas aeruginosa to methylotrophic bacteria and their detection in the new hosts.	several plasmids of incompatibility group p were transferred from escherichia coli and pseudomonas aeruginosa strains to methylophilus methylotrophus and two other methylotrophs to test their recipient ability. the presence of plasmids in transconjugants was confirmed by electrophoretic analysis. optimal conditions for detection of plasmid dna in the strains tested based on alkaline lysis of cells at elevated temperature were established. special behaviour of plasmids carrying the mu phage in me ...	1987	3121477
electron transfer flavoprotein from methylophilus methylotrophus: properties, comparison with other electron transfer flavoproteins, and regulation of expression by carbon source.	when grown on methylated amines as a carbon source, methylophilus methylotrophus synthesizes an electron transfer flavoprotein (etf) which is the natural electron acceptor of trimethylamine dehydrogenase. it is composed of two dissimilar subunits of 38,000 and 42,000 daltons and 1 mol of flavin adenine dinucleotide. it was reduced by trimethylamine dehydrogenase to a stable anionic semiquinone form, which could not be converted, either enzymatically or chemically, to the fully reduced dihydroqui ...	1986	3711024
on the dielectrically observable consequences of the diffusional motions of lipids and proteins in membranes. 2. experiments with microbial cells, protoplasts and membrane vesicles.	the dielectric properties of suspensions of intact cells of methylophilus methylotrophus, paracoccus denitrificans and bacillus subtilis have been measured in the frequency range 1 khz to 13 mhz. all possess a pronounced dispersion corresponding in magnitude and relaxation time to the "beta-dispersion" in a terminology defined by schwan [adv. biol. med. phys. 5:147-209 (1957)]. the latter two strains, but not m. methylotrophus, also possess a substantial alpha-dispersion. the relaxation time of ...	1985	3935420
expression of a chemically synthesized human alpha 1 interferon gene.	cells of escherichia coli containing a chemically synthesized human alpha 1 interferon (ifn-alpha 1) gene, under control of the lac promoter, make a product with biological properties indistinguishable from those of the natural ifn-alpha 1 [antiviral activity, acid stability, species crossreactivity, inactivation by antisera directed against leukocyte or namalwa cell interferon, and stimulation of (2'-5')oligoadenylate synthetase activity]. similar levels of ifn synthesis were obtained when the ...	1982	6181502
the purification and properties of the soluble cytochromes c of the obligate methylotroph methylophilus methylotrophus.	the obligate methylotroph methylophilus methylotrophus contains three distinct soluble cytochromes c. the major cytochromes, cytochrome ch (about 50% of the total) and cytochrome cl (about 42%), were similar in most respects to the cytochromes ch and cl of the facultative methylotroph pseudomonas am1 [o'keeffe & anthony (1980) biochem. j. 192, 411-419]. cytochrome ch had a high isoelectric point, a midpoint redox potential at ph 7.0 of 373 mv and a low molecular weight (8500). the cytochrome cl ...	1980	6263254
respiration-linked proton translocation in the obligate methylotroph methylophilus methylotrophus.	the stoicheiometries of respiration-linked proton translocation in methylophilus methylotrophus were determined by using both the oxygen-pulse and initial-rate methods. the latter has also been used to determine leads to charge/o quotients (measured as yield k+/o quotients) in order to ascertain whether the leads to h+/o quotients might be underestimated by h+/anion symport. the results suggest that 6h+/o are translocated during nadh oxidation, and that 2h+/o are translocated during the oxidatio ...	1981	6272739
the autoreducible cytochromes c of the methylotrophs methylophilus methylotrophus and pseudomonas am1.	the two types of soluble cytochrome c (cytochrome ch and cytochrome cl) found in methylotrophs are completely distinct proteins; one type is not a dimer or degradation product of the other. free thiol groups are probably not involved in the unusually rapid autoreduction of the cytochromes at high ph. the axial ligands to the haem iron, histidine and methionine, are the same as in other low-spin cytochromes c. the methionine ligand is displaced at high ph by an alternative strong-field ligand. th ...	1982	6295363
a broad-host-range cloning vector transposable to various replicons.	a system is described for the stable insertion of cloned dna sequences into the chromosomes of gram-negative bacteria. two broad-host-range plasmids form the basis of the system: one (the "carrier") contains a transposable dna sequence into which foreign dna can be cloned; the second (the "helper") provides transposition functions in trans. both plasmids can be readily transferred between gram-negative bacteria by conjugation. instability of the carrier allows enrichment for the products of tran ...	1983	6301943
the terminal respiratory chain of the methylotrophic bacterium methylophilus methylotrophus.	cytochrome oxidase o has been isolated from the obligately aerobic, methylotrophic bacterium methylophilus methylotrophus in the form of a cytochrome cl-o complex. the latter is comprised of cytochrome cl (mr 21 000) and cytochrome o (mr 29 000) in a 1-2:1 ratio, possibly in association with one or more minor polypeptides; the complex exhibits a high ascorbate-tmpd oxidase activity which is inhibited non-competitively by cyanide (ki approximately 2 microm). in contrast, the oxidation of methanol ...	1983	6303840
genetic mapping in methylophilus methylotrophus as1.	prime plasmids have been isolated from methylophilus methylotrophus as1 using the incp-1 plasmid pmo172. such plasmids can complement mutant function when transferred to appropriate strains of pseudomonas aeruginosa pao. from the range of particular functions complemented by each prime plasmid, a preliminary map of the m. methylotrophus as1 genome with four groups of linked markers was obtained. physical examination of two of these prime plasmids showed that each had acquired an additional dna s ...	1983	6308129
the effect of edta and related chelating agents on the oxidation of methanol by the methylotrophic bacterium, methylophilus methylotrophus.	the effects of edta and related metal-chelating agents on the respiratory system of the methylotrophic bacterium methylophilus methylotrophus have been investigated. edta completely inhibited whole cell methanol oxidase activity and concomitantly decreased the aerobic steady-state reduction level of cytochrome c, but only partially inhibited methanol dehydrogenase activity. analysis of the inhibition kinetics of edta and other chelating agents on methanol oxidase activity indicated that they wer ...	1984	6420156
improved conversion of methanol to single-cell protein by methylophilus methylotrophus.	the glutamate dehydrogenase gene of escherichia coli has been cloned into broad host-range plasmids and can complement glutamate synthase mutants of methylophilus methylotrophus. assimilation of ammonia via glutamate dehydrogenase is more energy-efficient than via glutamate synthase, thus the recombinant organism converts more growth substrate, methanol, into cellular carbon.	1980	6776410
purification and properties of the methanol dehydrogenase from methylophilus methylotrophus.	1. a dye-linked methanol dehydrogenase, resembling many others from a variety of methylotrophic bacteria, was purified to homogeneity from extracts of methanol-grown methylophilus methylotrophus. 2. the enzyme was very stable in the presence of methanol; in the absence of methanol it had a half-life of 1-2 days at 4 degrees c. 3. the value of a1% 1cm,280 was 17.5. 4. the enzyme retained bound methanol after passage through sephadex g-25. this tightly-bound methanol slowly exchanged with free [14 ...	1981	6802134
expression of eukaryotic coding sequences in methylophilus methylotrophus.		1982	6803176
possible regulation of the methanol dehydrogenase fro methylophilus methylotrophus by its oxidized electron acceptor.		1980	7004951
[properties of the obligate methylotroph methylophilus methanolovorus].	a strain of obligate methylotrophic bacteria utilizing methanol as a sole source of carbon and energy was isolated from the activated sludge. the bacteria are strictly aerobic gram-negative non-pigmented motile rods with a single polar flagellum. they do not form spores or capsules and have no complex intracytoplasmic membranes. they do not require vitamins and assimilate methanol via the hexulose phosphate pathway. the g+c content of dna is 51.0 +/- 0.5 mole%. the optimal temperature is 30-38 d ...	1981	7219216
the electron-transport chains of the obligate methylotroph methylophilus methylotrophus.	the cytochrome complement of methylophilus methylotrophus and its respiratory properties were determined during batch culture and in continuous culture under conditions of methanol-, nitrogen- and o(2)-limitation. about 35% of the cytochrome c produced by the bacteria was released into the growth medium, and of the remaining cytochrome c about half was membrane-bound and half was soluble. two cytochromes c were always present on membranes (redox potentials 375mv and 310mv), and these probably co ...	1980	7236221
energy conservation in the terminal region of the respiratory chain of the methylotrophic bacterium methylophilus methylotrophus.	reduced + co minus reduced difference spectra of respiratory membranes prepared from methanol-limited cultures of methylophilus methylotrophus confirm the presence of three co-binding cytochromes i.e. cytochromes aa3, o and cco. the kinetics of cyanide inhibition indicate that the respiratory chain of this organism is branched at the level of cytochrome c to two major terminal oxidases, viz. cytochromes aa3 and o; cytochrome cco is probably not a physiologically significant oxidase. determinatio ...	1981	7285910
the primary structure of hyphomicrobium x dimethylamine dehydrogenase. relationship to trimethylamine dehydrogenase and implications for substrate recognition.	the gene encoding dimethylamine dehydrogenase from hyphomicrobium x has been cloned and over-expressed in escherichia coli. using the chemically determined protein sequence, primers were designed to amplify dna fragments encoding the proximal and distal parts of the gene. these fragments were used to synthesise two probes and the dmd gene was cloned as part of two bamhi fragments isolated from digested genomic dna. the sequence of the complete open reading frame was determined on both strands an ...	1995	7556160
mmei, a class-iis restriction endonuclease: purification and characterization.	two restriction endonucleases, mmei and mmeii, from methylophilus methylotrophus were purified to homogeneity. both enzymes belong to the class-ii restriction endonucleases (enases) but exhibit very different enzymatic and physical properties. mmeii is a typical member of class-ii enases. it is a polymeric protein composed of 50-kda subunits. in contrast to mmeii, mmei is a monomeric protein of 101 kda, cleaving a dna molecule 20/18 nucleotides away from the asymmetric recognition sequence (5'-t ...	1995	7607532
cloning, sequencing, and mutation of a gene for azurin in methylobacillus flagellatum kt.	the gene cluster for methylamine utilization (mau genes) has been cloned from the obligate methylotrophic bacterium methylobacillus flagellatum kt. partial sequence data showed that the organization of these genes was similar to that found in methylophilus methylotrophus w3a1-ns, including the lack of a gene for amicyanin, which had been thought to be the electron acceptor for methylamine dehydrogenase in m. flagellatum kt. however, a gene encoding azurin was discovered at the 3' end of the mau ...	1995	7635847
the flavinylation reaction of trimethylamine dehydrogenase. analysis by directed mutagenesis and electrospray mass spectrometry.	the flavinylation reaction products of wild-type and mutant forms of trimethylamine dehydrogenases purified from methylophilus methylotrophus (bacterium w3a1) and escherichia coli were studied by electrospray mass spectrometry (esms). the esms analyses demonstrated for the first time that wild-type enzyme expressed in m. methylotrophus is predominantly in the holoenzyme form, although a small proportion is present as the deflavo enzyme. esms demonstrated that the deflavo forms of the recombinant ...	1995	7768915
cloning, sequence analysis, and expression of the genes encoding the two subunits of the methylotrophic bacterium w3a1 electron transfer flavoprotein.	the genes encoding the two different subunits of the electron transfer flavoprotein (etf) from the methylotrophic bacterium w3a1 have been identified, cloned, and sequenced. a 0.8-kilobase pair dna fragment was generated for use as a molecular probe by the amplification of genomic sequences using the polymerase chain reaction and a primer pair with degenerate sequences derived from the nh2-terminal amino acid sequences determined for the etf subunits purified from w3a1. the screening of a partia ...	1994	7798207
genetic organization of the mau gene cluster in methylobacterium extorquens am1: complete nucleotide sequence and generation and characteristics of mau mutants.	the nucleotide sequence of the methylamine utilization (mau) gene region from methylobacterium extorquens am1 was determined. open reading frames for 11 genes (maufbedacjglmn) were found, all transcribed in the same orientation. the maub, maua, and mauc genes encode the periplasmic methylamine dehydrogenase (madh) large and small subunit polypeptides and amicyanin, respectively. the products of maud, maug, maul, and maum were also predicted to be periplasmic. the products of mauf, maue, and maun ...	1994	8021187
organization of the methylamine utilization (mau) genes in methylophilus methylotrophus w3a1-ns.	the organization of genes involved in utilization of methylamine (mau genes) was studied in methylophilus methylotrophus w3a1. the strain used was a nonmucoid variant termed ns (nonslimy). the original mucoid strain was shown to be identical to the ns strains on the basis of chromosomal digest and hybridization patterns. an 8-kb psti fragment of the chromosome from m. methylotrophus w3a1-ns encoding the mau genes was cloned and a 6,533-bp region was sequenced. eight open reading frames were foun ...	1994	8021188
crystallization and preliminary crystallographic investigation of electron-transfer flavoprotein from the bacterium methylophilus w3a1.	electron-transfer flavoprotein from methylophilus w3a1 has been crystallized using the sitting drop vapour diffusion technique. hexagonal crystals, suitable for high-resolution structure determination grow to approximately 0.7 mm x 0.7 mm x 0.5 mm in size and diffract to at least 2.2 a. the space group is either p6(1) or p6(5) with unit cell dimensions a,b = 119.1 a and c = 85.6 a.	1994	8028009
an unusual conformation of the methionine haem ligand in cytochrome cl established by two-dimensional 1h-nmr.	a complete relaxation-matrix analysis of noesy cross-peak intensities was used to determine the conformation of the methionine ligand to the haem group in two ferrocytochromes cl from methylophilus methylotrophus and methylobacterium extorquens, including the configuration at the sulphur. the conformation of the axial methionine is of a type reported only for the cytochromes c5 from pseudomonas mendocina and azotobacter vinelandii. although the conformation of the methionine is unusual, the para ...	1994	8055954
reaction of rat liver glutathione s-transferases and bacterial dichloromethane dehalogenase with dihalomethanes.	dichloromethane dehalogenase from methylophilus sp. dm11 is a glutathione s-transferase homolog that is specifically active with dihalomethane substrates. this bacterial enzyme and rat liver glutathione s-transferases were purified to investigate their relative reactivity with ch2cl2 and related substrates. rat liver alpha class glutathione transferases were inactive and mu class enzymes showed low activity (7-23 nmol/min/mg of protein) with ch2cl2. theta class glutathione transferase 5-5 from r ...	1994	8132617
isolation and characterization of the methylophilus sp. strain dm11 gene encoding dichloromethane dehalogenase/glutathione s-transferase.	the restricted facultative methylotroph methylophilus sp. strain dm11 utilizes dichloromethane as the sole carbon and energy source. it differs from other dichloromethane-utilizing methylotrophs by faster growth on this substrate and by possession of a group b dichloromethane dehalogenase catalyzing dechlorination at a fivefold-higher rate than the group a enzymes of slow-growing strains. we isolated dcma, the structural gene of the strain dm11 dichloromethane dehalogenase, to elucidate its rela ...	1994	8206823
haloacetonitriles are low k1 inhibitors of bacterial dichloromethane dehalogenases.	distinct dichloromethane dehalogenases from methylobacterium sp. strain dm4 and methylophilus dm11 were inhibited by low concentrations of haloacetonitriles. chloroacetonitrile (clch2cn) showed maximal inhibition at a stoichiometry of 1 mol inhibitor:1 mol holoenzyme for both enzymes. this stoichiometry is suggestive of one active site per holoenzyme or extreme negative cooperativity amongst the subunits. radiolabelled clch2cn dissociated completely or partially from the two dehalogenases, respe ...	1993	8267624
characterization of the haem environment in methylophilus methylotrophus ferricytochrome c" by 1h-nmr.	two-dimensional nmr techniques have been used to assign proton resonances in the haem cavity of methylophilus methylotrophus cytochrome c", a monohaem protein with bis-histidinyl ligation which has been shown to couple electron and proton transfer. all the assignments were made directly for the oxidized paramagnetic form of the cytochrome. nearly all of the haem protons (90%) and the protons of both axial ligands have been assigned; the side-chain protons from four other residues in the haem poc ...	1993	8394812
identification of methanol-regulated promoter sequences from the facultative methylotrophic bacterium methylobacterium organophilum xx.	a promoter-probe vector (phx200) was constructed using the broad-host-range cosmid pla2917 and a promoterless xyle gene of pseudomonas as the reporter gene. insertion of the cloned promoter fragment of the methanol dehydrogenase large subunit gene moxf (methanol oxidation) in front of the xyle gene in phx200v-47 resulted in high-level expression of the xyle gene product--catechol 2,3-dioxygenase--in methylobacterium organophilum xx. the specific activity of the enzyme was four times higher in me ...	1993	8515233
a high-potential soluble cytochrome c-551 from the purple phototrophic bacterium chromatium vinosum is homologous to cytochrome c8 from denitrifying pseudomonads.	a minor cytochrome c-551 component of chromatium vinosum was previously found to efficiently couple electron transfer between the cytochrome bc1 complex and the photosynthetic reaction center. we have now determined the amino acid sequence of this cytochrome c-551 and find that it is homologous to cytochrome c8 (formerly called pseudomonas cytochrome c-551). it is most similar to methylophilus methylotrophus, rhodocyclus tenuis, and azotobacter vinelandii cytochromes c8 (respectively, 57%, 52% a ...	1996	8612646
physical, biochemical, and immunological characterization of a thermostable amidase from klebsiella pneumoniae nctr 1.	an amidase capable of degrading acrylamide and aliphatic amides was purified to apparent homogeneity from klebsiella pneumoniae nctr 1. the enzyme is a monomer with an apparent molecular weight of 62,000. the ph and temperature optima of the enzyme were 7.0 and 65 degrees c, respectively. the purified amidase contained 11 5,5-dithiobis(2-nitrobenzoate) (dtnb)-titratable sulfhydryl (sh) groups. in the native enzyme 1.0 sh group readily reacted with dtnb with no detectable loss of activity. titrat ...	1996	8636044
determination of the gene sequence and the three-dimensional structure at 2.4 angstroms resolution of methanol dehydrogenase from methylophilus w3a1.	the dna sequences for the genes encoding the heavy and light subunits of methanol dehydrogenase from methylophilus methylotrophus w3a1 have been determined. the deduced amino acid sequence has enabled the structure of the enzyme to be refined at 2.4 angstrom resolution against x-ray data collected on a hamlin area detector. the structure was refined using the programs profft and x-plor with several model building step interspersed. the final model contains two heavy chains (571 amino acids), two ...	1996	8676383
protein engineering studies of dichloromethane dehalogenase/glutathione s-transferase from methylophilus sp. strain dm11. ser12 but not tyr6 is required for enzyme activity.	the structural gene for dichloromethane dehalogenase/glutathione s-transferase (gst, ec 2.5.1.18) from methylophilus sp. strain dm11 was subcloned into a multicopy plasmid under the control of the t7 polymerase promoter, allowing expression in escherichia coli and easy purification of the enzyme in good yield. several point mutations leading to amino acid changes at residues tyr6, his8 and ser12 of the protein were introduced in this gene. mutations at tyr6, the n-terminal tyrosine known to be e ...	1996	8706748
molecular characterisation of formamidase from methylophilus methylotrophus.	a 3.2-kbp psti fragment of dna encoding formamidase from the methylotrophic bacterium methylophilus methylotrophus which had previously been cloned (pnw3) [wyborn, n.r., scherr, d.j. & jones, c.w. (1994) microbiology 140, 191-195], was subcloned as a 2.3 kbp hindiii fragment (pnw323). nucleotide sequencing showed that the subclone contained two genes which encoded formamidase (fmda) and a possible regulatory protein (fmdb). predicted molecular masses for fmda and fmdb were 44438 da (compared wit ...	1996	8841393
improved large scale culture of methylophilus methylotrophus for 13c/15n labeling and random fractional deuteration of ribonucleotides.	isotopic labeling of rna with 13c and 15n has become a routine procedure in structural studies by nmr spectroscopy. the methodology in this paper describes the random fractional deuteration of rna using the obligate methylotropic bacterium, methylophilus methylotrophus. this bacterium was grown using a non-deuterated carbon source in 52:48 d20/h20 and we have shown that all protons in the ribonucleotides except for the ribose h1 become 52% randomly fractionally deuterated. improved growth condit ...	1996	8972874
transformation of methylotrophic bacteria by electroporation.	an efficient system for electroporation of the methylotrophic bacteria hyphomicrobium facilis, hyphomicrobium denitrificans, methylobacillus glycogenes, methylobacterium extorquens, and methylophilus methylotrophus is described. it could be demonstrated that vectors based on the broad-host-range plasmid pbbr1 could be transferred into these strains. plasmid pbbr1kan (3.9 kb), a kanamycin-resistant derivative of pbbr1, was suitable for transformation experiments in these methylotrophic bacteria. ...	1997	9090108
knowledge-based modeling of a bacterial dichloromethane dehalogenase.	a three-dimensional structural model of the dichloromethane dehalogenase (dcmd) from methylophilus sp. dm11 is constructed based on sequence similarities to the glutathione s-transferases (gsts). to maximize sequence identity and minimize gaps in the alignment, a hybrid approach is used that takes advantage of the increased homology found between dm11 and domain i of the sheep blowfly theta class gst (residues 1-79) and domain ii of the human alpha class gst (residues 81-222). the resulting stru ...	1997	9188739
an outer-membrane porin inducible by short-chain amides and urea in the methylotrophic bacterium methylophilus methylotrophus.	the fmda and fmdb genes encoding formamidase and a putative regulatory protein, respectively, from the methylotrophic bacterium methylophilus methylotrophus were recloned with additional flanking dna (psw1). fmdc, encoding a weakly hydrophilic protein containing an n-terminal signal sequence, was identified upstream of fmdab. the derived amino acid sequence of mature fmdc (m(r) 39204) showed that it was rich in beta-sheet and aromatic amino acids, and exhibited significant similarities to severa ...	1997	9245819
creating auxotrophic mutants in methylophilus methylotrophus as1 by combining electroporation and chemical mutagenesis.	stable auxotrophic mutants of the methylotroph methylophilus methylotrophus as1 were obtained by a novel mutagenesis technique in which electroporation is used to transport the chemical mutagen n-methyl-n'-nitro-n-nitrosoguanidine (mnng) across the cell membrane. by combining chemical mutagenesis with electroporation and screening single colonies for auxotrophy in 36 different amino acids and growth factors, 3 auxotrophs per 156 colonies screened were obtained, whereas no auxotrophs were found w ...	1997	9274053
identification of a novel determinant of glutathione affinity in dichloromethane dehalogenases/glutathione s-transferases.	bacterial dichloromethane dehalogenases catalyze the glutathione-dependent hydrolysis of dichloromethane to formaldehyde and are members of the enzyme superfamily of glutathione s-transferases involved in the detoxification of electrophilic compounds. numerous protein engineering studies have addressed questions pertaining to the substrate specificity, the reaction mechanism, and the kinetic pathway of glutathione s-transferases. in contrast, the molecular determinants for binding of the glutath ...	1997	9299530
cloning and analysis of methanol oxidation genes in the methylotroph hyphomicrobium methylovorum gm2.	the gene encoding the alpha-subunit of methanol dehydrogenase (mxaf) and its flanking region was isolated from a methylotrophic bacterium, hyphomicrobium methylovorum gm2. the deduced amino acid sequence of mxaf showed 80, 80, 74 and 66% identity with those of methylobacterium extorquens am1, m. organophilum xx, paracoccus denitrificans and methylophilus methylotrophus, respectively. the putative mxaf promoter sequence (-35 -aaagaca-, -10 -tagaa-) observed in other methylotrophs was not found in ...	1997	9311140
ph dependence of structural and functional properties of oxidized cytochrome c" from methylophilus methylotrophus.	cytochrome c" from methylophilus methylotrophus is an unusual monoheme protein that undergoes a major redox-linked change in the heme arrangement: one of the two axial histidines bound to the iron in the oxidized form is detached upon reduction and a proton is taken up. the kinetics of reduction by sodium dithionite and the spectroscopic properties of the oxidized cytochrome c" have been investigated over the ph range between 1.4 and 10.0. the rate of reduction displays proton-linked transitions ...	1997	9312076
characterisation of a binding-protein-dependent, active transport system for short-chain amides and urea in the methylotrophic bacterium methylophilus methylotrophus.	three genes (fmdcab) encoding an outer-membrane porin for short-chain amides and urea, formamidase, and a putative regulatory protein in methylophilus methylotrophus have previously been cloned and characterised. three genes have now been identified downstream of fmdb, viz fmdd encoding a hydrophilic protein containing an n-terminal signal sequence, and fmdef encoding hydrophobic transmembrane proteins. the derived amino acid sequence of mature fmdd (predicted molecular mass 41,870 da) was simil ...	1998	9492267
effects of bacterial host and dichloromethane dehalogenase on the competitiveness of methylotrophic bacteria growing with dichloromethane.	methylobacterium sp. strain dm4 and methylophilus sp. strain dm11 can grow with dichloromethane (dcm) as the sole source of carbon and energy by virtue of homologous glutathione-dependent dcm dehalogenases with markedly different kinetic properties (the kcat values of the enzymes of these strains are 0.6 and 3.3 s-1, respectively, and the km values are 9 and 59 microm, respectively). these strains, as well as transconjugant bacteria expressing the dcm dehalogenase gene (dcma) from dm11 or dm4 on ...	1998	9546153
homology model of the quinohaemoprotein alcohol dehydrogenase from comamonas testosteroni.	a molecular model of qh-adh, the quinohaemoprotein alcohol dehydrogenase from comamonas testosteroni, has been built by homology modelling. sequence similarity of n-terminal residues 1-570 with the alpha-subunit of quinoprotein methanol dehydrogenases (mdhs) from methylophilus methylotrophus w3a1 and methylobacterium extorquens provided a basis for the design of the pqq-binding domain of qh-adh. minimal sequence similarity with cytochrome c551 from ectothiorhodospira halophila and cytochrome c5 ...	1998	9613842
two intertwined methylation activities of the mmei restriction-modification class-iis system from methylophilus methylotrophus.	the class-iis restriction endonuclease, r.mmei, was isolated from methylophilus methylotrophus. it was originally described as a monomeric enzyme, with the native mr 105000+/-7000, which did not cleave dna efficiently [boyd et al. (1986) nucleic acids res. 14, 5255-5274; tucholski et al. (1995) gene 157, 87-92]. however, it was discovered that r.mmei endonucleolytic activity is enhanced by s-adenosyl-l-methionine (adomet) and sinefungin, an analogue of adomet. surprisingly, the purified r.mmei e ...	1998	9858752
detailed active site configuration of a new crystal form of methanol dehydrogenase from methylophilus w3a1 at 1.9 a resolution.	the three-dimensional structure of a new crystal form of methanol dehydrogenase from methylophilus w3a1 has been obtained in the presence of substrate using data recorded at a synchrotron. the structure of this approximately 140 kda heterotetramer, refined at 1. 9 a resolution, reveals the detailed configuration of its redox cofactor, pyrroloquinoline quinone (pqq). c4, one of the oxygen-bearing atoms of this orthoquinone is in a planar configuration while c5, which bears the other quinone oxyge ...	1999	9930981
enzymatic h-transfer requires vibration-driven extreme tunneling.	enzymatic breakage of the substrate c-h bond by methylophilus methyltrophus (sp. w3a1) methylamine dehydrogenase (madh) has been studied by stopped-flow spectroscopy. the rate of reduction of the tryptophan tryptophylquinone (ttq) cofactor has a large kinetic isotope effect (kie = 16.8 +/- 0.5), and the kie is independent of temperature. analysis of the temperature dependence of c-h bond breakage revealed that extreme (ground state) quantum tunneling is responsible for the transfer of the hydrog ...	1999	10074378
purification and characterization of the mutant enzyme w117y of the dichloromethane dehalogenase from methylophilus sp. strain dm11.		1998	10075637
the reaction of trimethylamine dehydrogenase with trimethylamine.	the reductive half-reaction of trimethylamine dehydrogenase with its physiological substrate trimethylamine has been examined by stopped-flow spectroscopy over the ph range 6.0-11.0, with attention focusing on the fastest of the three kinetic phases of the reaction, the flavin reduction/substrate oxidation process. as in previous work with the slow substrate diethylmethylamine, the reaction is found to consist of three well resolved kinetic phases. the observed rate constant for the fast phase e ...	1999	10224069
enzyme-mediated dichloromethane toxicity and mutagenicity of bacterial and mammalian dichloromethane-active glutathione s-transferases.	the kinetic properties of bacterial and rat liver glutathione s-transferases (gst) active with dichloromethane (dcm) were compared. the theta class glutathione s-transferase (rgstti-1) from rat liver had an affinity for dihalomethanes lower by three orders of magnitude (k(app) > 50 mm) than the bacterial dcm dehalogenase/gst from methylophilus sp. dm11. unlike the bacterial dcm dehalogenase, the rat enzyme was unable to support growth of the dehalogenase minus methylobacterium sp. dm4-2cr mutant ...	1999	10350186
cytochrome c" from the obligate methylotroph methylophilus methylotrophus, an unexpected homolog of sphaeroides heme protein from the phototroph rhodobacter sphaeroides.	the complete primary structure of an unusual soluble cytochrome c isolated from the obligate methylotrophic bacterium methylophilus methylotrophus has been determined to contain 124 amino acids and to have an average molecular mass of 14293.0 da. the sequence has two unusual features: firstly, the location of the heme-binding cysteines is far downstream from the n-terminus, namely at positions 49 and 52; secondly, an extra pair of cysteine residues is present near the c-terminus. in both respect ...	1999	10354493
cloning and sequence analysis of the gene encoding methylophilus methylotrophus cytochrome c", a unique protein with a perpendicular orientation of the histidinyl ligands.	cytochrome c" from methylophilus methylotrophus is an unusual monohaem protein that undergoes a major redox-linked spin-state transition: one of the two axial histidines bound to the iron in the oxidised form is detached upon reduction and a proton is taken up. a 3.5-kb dna fragment, containing the gene encoding cytochrome c" (cyca), has been cloned and sequenced. the cytochrome c" gene codes for a pre-protein with a typical prokaryotic 20-residue signal sequence, suggesting that the protein is ...	1999	10524262
crystallization and preliminary diffraction studies of two quinoprotein alcohol dehydrogenases (adhs): a soluble monomeric adh from pseudomonas putida hk5 (adh-iib) and a heterotrimeric membrane-bound adh from gluconobacter suboxydans (adh-gs).	crystals of a soluble monomeric quinocytochrome alcohol dehydrogenase (adh-iib) and of a trimeric membrane-associated quinocytochrome alcohol dehydrogenase (adh-gs) have been obtained. the adh-iib crystals are triclinic, with one monomer in the unit cell, and were obtained in the presence of peg 8000, sodium citrate, hepes buffer and 2-propanol. x-ray data were collected at 110 k to 1. 9 a resolution (r(merge) = 6.4%) and the orientation of a methanol dehydrogenase search molecule (from methylop ...	1999	10531500
structure of the phylogenetically most conserved domain of srp rna.	the signal recognition particle (srp) is a phylogenetically conserved ribonucleoprotein required for cotranslational targeting of proteins to the membrane of the endoplasmic reticulum of the bacterial plasma membrane. domain iv of srp rna consists of a short stem-loop structure with two internal loops that contain the most conserved nucleotides of the molecule. all known essential interactions of srp occur in that moiety containing domain iv. the solution structure of a 43-nt rna comprising the ...	1999	10580470
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
x-ray scattering studies of methylophilus methylotrophus (sp. w3a1) electron-transferring flavoprotein. evidence for multiple conformational states and an induced fit mechanism for assembly with trimethylamine dehydrogenase.	small angle x-ray solution scattering has been used to generate a low resolution, model-independent molecular envelope structure for electron-transferring flavoprotein (etf) from methylophilus methylotrophus (sp. w(3)a(1)). analysis of both the oxidized and 1-electron-reduced (anionic flavin semiquinone) forms of the protein revealed that the solution structures of the protein are similar in both oxidation states. comparison of the molecular envelope of etf from the x-ray scattering data with pr ...	2000	10766748
formation of w(3)a(1) electron-transferring flavoprotein (etf) hydroquinone in the trimethylamine dehydrogenase x etf protein complex.	the electron-transferring flavoprotein (etf) from methylophilus methylotrophus (sp. w(3)a(1)) exhibits unusual oxidation-reduction properties and can only be reduced to the level of the semiquinone under most circumstances (including turnover with its physiological reductant, trimethylamine dehydrogenase (tmadh), or reaction with strong reducing reagents such as sodium dithionite). in the present study, we demonstrate that etf can be reduced fully to its hydroquinone form both enzymatically and ...	2000	10777543
crystal structures of an oxygen-binding cytochrome c from rhodobacter sphaeroides.	the photosynthetic bacterium rhodobacter sphaeroides produces a heme protein (shp), which is an unusual c-type cytochrome capable of transiently binding oxygen during autooxidation. similar proteins have not only been observed in other photosynthetic bacteria but also in the obligate methylotroph methylophilus methylotrophus and the metal reducing bacterium shewanella putrefaciens. a three-dimensional structure of shp was derived using the multiple isomorphous replacement phasing method. besides ...	2000	10821858
radiolytic studies of trimethylamine dehydrogenase. spectral deconvolution of the neutral and anionic flavin semiquinone, and determination of rate constants for electron transfer in the one-electron reduced enzyme.	trimethylamine dehydrogenase from the pseudomonad methylophilus methylotrophus has been examined using the technique of pulse radiolysis to rapidly introduce a single reducing equivalent into the enzyme. using enzyme that has had its iron-sulfur center rendered redox-inert by prior reaction with ferricenium hexafluorophosphate, we determined the spectral change associated with formation of both the anionic and neutral forms that were generated at high and low ph, respectively, of the unique 6-cy ...	2000	10859304
structural and biochemical characterization of recombinant wild type and a c30a mutant of trimethylamine dehydrogenase from methylophilus methylotrophus (sp. w(3)a(1)).	trimethylamine dehydrogenase (tmadh) is an iron-sulfur flavoprotein that catalyzes the oxidative demethylation of trimethylamine to form dimethylamine and formaldehyde. it contains a unique flavin, in the form of a 6-s-cysteinyl fmn, which is bent by approximately 25 degrees along the n5-n10 axis of the flavin isoalloxazine ring. this unusual conformation is thought to modulate the properties of the flavin to facilitate catalysis, and has been postulated to be the result of covalent linkage to c ...	2000	10869173
effect of ph on axial ligand coordination of cytochrome c" from methylophilus methylotrophus and horse heart cytochrome c.	the effect of protons on the axial ligand coordination and on structural aspects of the protein moiety of cytochrome c' ' from methylophilus methylotrophus, an obligate methylotroph, has been investigated down to very low ph (i.e., 0.3). the unusual resistance of this cytochrome to very low ph values has been exploited to carry out this study in comparison with horse heart cytochrome c. the experiments were undertaken at a constant phosphate concentration to minimize the variation of ionic stren ...	2000	10889031
differential coupling through val-344 and tyr-442 of trimethylamine dehydrogenase in electron transfer reactions with ferricenium ions and electron transferring flavoprotein.	modeling studies of the trimethylamine dehydrogenase-electron transferring flavoprotein (tmadh-etf) electron transfer complex have suggested potential roles for val-344 and tyr-442, found on the surface of tmadh, in electronic coupling between the 4fe-4s center of tmadh and the fad of etf. the importance of these residues in electron transfer, both to etf and to the artificial electron acceptor, ferricenium (fc(+)), has been studied by site-directed mutagenesis and stopped-flow spectroscopy. red ...	2000	10924112
solution structure and metal-ion binding of the p4 element from bacterial rnase p rna.	we determined the solution structure of two 27-nt rna hairpins and their complexes with cobalt(iii)-hexammine (co(nh3)3+(6)) by nmr spectroscopy. the rna hairpins used in this study are the p4 region from escherichia coli rnase p rna and a c-to-u mutant that confers altered divalent metal-ion specificity (ca2+ replaces mg2+) for catalytic activity of this ribozyme. co(nh3)3+(6) is a useful spectroscopic probe for mg(h2o)2+(6)-binding sites because both complexes have octahedral symmetry and have ...	2000	10999599
high yield of methylophilus methylotrophus cytochrome c by coexpression with cytochrome c maturation gene cluster from escherichia coli.	heterologous expression of c-type cytochromes in the periplasm of escherichia coli often results in low soluble product yield, apoprotein formation, or protein degradation. we have expressed cytochrome c from methylophilus methylotrophus in e. coli by coexpression of the gene encoding the cytochrome (cyca) with the host-specific cytochrome c maturation elements, within the ccma-h gene cluster. aerobic cultures produced up to 10 mg holoprotein per liter after induction with iptg. in the absence o ...	2000	11087684
catalytic mechanism of quinoprotein methanol dehydrogenase: a theoretical and x-ray crystallographic investigation.	the catalytic mechanism of the reductive half reaction of the quinoprotein methanol dehydrogenase (mdh) is believed to proceed either through a hemiketal intermediate or by direct transfer of a hydride ion from the substrate methyl group to the cofactor, pyrroloquinoline quinone (pqq). a crystal structure of the enzyme-substrate complex of a similar quinoprotein, glucose dehydrogenase, has recently been reported that strongly favors the hydride transfer mechanism in that enzyme. a theoretical an ...	2001	11149955
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
alpha arg-237 in methylophilus methylotrophus (sp. w3a1) electron-transferring flavoprotein affords approximately 200-millivolt stabilization of the fad anionic semiquinone and a kinetic block on full reduction to the dihydroquinone.	the midpoint reduction potentials of the fad cofactor in wild-type methylophilus methylotrophus (sp. w3a1) electron-transferring flavoprotein (etf) and the alphar237a mutant were determined by anaerobic redox titration. the fad reduction potential of the oxidized-semiquinone couple in wild-type etf (e'(1)) is +153 +/- 2 mv, indicating exceptional stabilization of the flavin anionic semiquinone species. conversion to the dihydroquinone is incomplete (e'(2) < -250 mv), because of the presence of b ...	2001	11285259
[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
solution structure of methylophilus methylotrophus cytochrome c": insights into the structural basis of haem-ligand detachment.	cytochrome c" from methylophilus methylotrophus is a monohaem protein with 124 amino acid residues. the iron has two histidine ligands in the oxidised form, one of which detaches and picks up a proton when the protein is reduced. thus, both forms are paramagnetic. the structure of the oxidised form in solution, determined from nmr data is presented. the family of structures has an average backbone rmsd value of 0.53 a, and a heavy atom rmsd value of 0.95 a, within a target function range of 32 % ...	2001	11327772
[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
inactivation of c30a trimethylamine dehydrogenase by n-cyclopropyl-alpha-methylbenzylamine, 1-phenylcyclopropylamine, and phenylhydrazine.	trimethylamine dehydrogenase (tmadh) from the bacterium methylophilus methylotrophus (sp. w(3)a(1)) and its c30a mutant were inactivated with three known inactivators of monoamine oxidase, namely, phenylhydrazine, n-cyclopropyl-alpha-methylbenzylamine, and 1-phenylcyclopropylamine. all three compounds irreversibly inactivated both the wild-type and c30a mutant enzymes, although phenylhydrazine was 10 times more potent than n-cyclopropyl-alpha-methylbenzylamine, which was much more potent than 1- ...	2001	11456490
a novel directly coupled gradostat.	the original bidirectional compound chemostat (gradostat) described by lovitt and wimpenny has been simplified by making a more compact apparatus in which chemical gradients are established by diffusion between adjacent culture chambers. the experimental model (diffusion coupled (dc) gradostat) consisted of five chambers whose contents could be agitated by turbines rotating in the horizontal plane on a common shaft. two biological experiments were designed to reveal the value of the dc gradost ...	1992	11540058
enzymes of dimethylsulfone metabolism and the phylogenetic characterization of the facultative methylotrophs arthrobacter sulfonivorans sp. nov., arthrobacter methylotrophus sp. nov., and hyphomicrobium sulfonivorans sp. nov.	novel methylotrophic arthrobacter and hyphomicrobium species are described. constitutive membrane-associated dimethylsulfone- and dimethylsulfoxide-reductases were found in arthrobacter methylotrophus strain tga and hyphomicrobium sulfonivorans strain s1. enzyme activities increased during growth with dimethylsulfone or dimethylsulfoxide, respectively, and different ratios of activity with different growth substrates indicated that they are separate enzymes. sds-page showed some membrane-associa ...	2002	11807567
identification of klebsiella pneumoniae genes involved in intestinal colonization and adhesion using signature-tagged mutagenesis.	klebsiella pneumoniae is an opportunistic pathogen responsible for nosocomial infections that initially colonize the intestinal tract of patients. signature-tagged mutagenesis was used to identify genes required for this function. a library of 2,200 mutants was analyzed for the inability of the mutants to survive in a murine model of intestinal colonization and to adhere to human intestinal cells (int-407) in vitro. twenty-nine attenuated mutants were selected for further analyses after competit ...	2002	12117993
[site-directed mutagenesis of the dichloromethane dehalogenase gene from methylophilus sp. strain dm11].	in order to investigate the role of different residues of methylophilus sp. strain dm11 dichloromethane dehalogenase for substrate binding, glutathione affinity, and catalytic activity, site-directed mutagenesis studies of the gene encoding the enzyme were carried out. the conserved tryptophane residue at 103 region was respectively substituted by phenylalanine, valine or asparagine. the conserved arginine residue at 109 region was substituted by leucine. the conserved tryptophane residue at 117 ...	1998	12549326
extensive conformational sampling in a ternary electron transfer complex.	here we report the crystal structures of a ternary electron transfer complex showing extensive motion at the protein interface. this physiological complex comprises the iron-sulfur flavoprotein trimethylamine dehydrogenase and electron transferring flavoprotein (etf) from methylophilus methylotrophus. in addition, we report the crystal structure of free etf. in the complex, electron density for the fad domain of etf is absent, indicating high mobility. positions for the fad domain are revealed b ...	2003	12567183
crystallization and preliminary x-ray characterization of cytochrome c" from the obligate methylotroph methylophilus methylotrophus.	cytochrome c" from the obligate methylotroph methylophilus methylotrophus is a 15 kda monohaem protein which has a c-type haem covalently linked to the protein chain. two histidine residues are the axial ligands of the fe atom in the oxidized form. this cytochrome is one of the few known haem proteins which undergoes a change of spin state of the fe atom upon reduction, with the detachment of an axial histidine ligand. initial crystallization conditions involved the utilization of cadmium chlori ...	2003	12595732
effects of multiple ligand binding on kinetic isotope effects in pqq-dependent methanol dehydrogenase.	the reaction of pqq-dependent methanol dehydrogenase (mdh) from methylophilus methylotrophus has been studied by steady-state and stopped-flow kinetic methods, with particular reference to multiple ligand binding and the kinetic isotope effect (kie) for pqq reduction. phenazine ethosulfate (pes; an artificial electron acceptor) and cyanide (a suppressant of endogenous activity), but not ammonium (an activator of mdh), compete for binding at the catalytic methanol-binding site. cyanide does not a ...	2003	12667088
catalytic mechanism of dichloromethane dehalogenase from methylophilus sp. strain dm11.	the glutathione (gsh)-dependent dichloromethane dehalogenase from methylophilus sp. strain dm11 catalyzes the dechlorination of ch(2)cl(2) to formaldehyde via a highly reactive, genotoxic intermediate, s-(chloromethyl)glutathione (gs-ch(2)cl). the catalytic mechanism of the enzyme toward a series of dihalomethane and monohaloethane substrates suggests that the initial addition of gsh to the alkylhalides is fast and that the rate-limiting step in turnover is the release of either the peptide prod ...	2003	12974641