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purification and properties of the methane mono-oxygenase enzyme system from methylosinus trichosporium ob3b.1. a three-component enzyme system that catalyses the oxidation of methane to methanol has been highly purified from methylosinus trichosporium. 2. the components are (i) a soluble co-binding cytochrome c, (ii) a copper-containing protein and (iii) a small protein; the mol. wts. are 13 000, 47 000 and 9400 respectively. the cytochrome component cannot be replaced by similar cytochrome purified from pseudomonas extorquens or by horse heart cytochrome c. 3. the stoicheiometry suggests a mono-oxyge ...197715544
fructose metabolism in four pseudomonas species.1. atp-dependent phosphorylation of fructose could not be detected in extracts of fructose-grown cells of pseudomonas extorquens strain 16, pseudomonas 3a2, pseudomonas acidovorans and pseudomonas fluorescens. instead, phosphorylation of fructose to fructose-1-phosphate was found to occur when cell-free extracts were incubated with fructose and phosphoenolpyruvate. such an activity could not be detected in cell-free extracts of succinate-grown cells. 2. high levels of 1-phosphofructokinase were ...1977143919
bacterial flora of the schistosome vector snail biomphalaria glabrata.the aerobic heterotrophic bacterial flora in over 200 individuals from 10 wild populations and 3 laboratory colonies of the schistosome vector snail biomphalaria glabrata was examined. internal bacterial densities were inversely proportional to snail size and were higher in stressed and laboratory-reared snails. the numerically predominant bacterial genera in individual snails included pseudomonas, acinetobacter, aeromonas, vibrio, and several members of the enterobacteriaceae. enterobacteriacea ...1979539821
the microbial metabolism of c1 compounds. the electron-transport chain of pseudomonas am1.pseudomonas am1, hyphomicrobium x and pseudomonas ms all contain cytochrome a/a(3) and a b-type cytochrome able to react with co. pseudomonas am1 and hyphomicrobium x also have a co-binding cytochrome c. the purified cytochrome c (redox potential 0.26v) of pseudomonas am1 was not susceptible to oxidation by molecular oxygen. co reacted slowly with the reduced form giving a co difference spectrum with a peak at 412nm and troughs at 420nm and 550nm. similar results were obtained with the cytochrom ...19751220689
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 ...19921311606
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 ...19921331050
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 ...19921332681
crystallization and preliminary crystallographic investigation of methanol dehydrogenase from methylobacterium extorquens am1.single crystals of methanol dehydrogenase (mdh) from methylobacterium extorquens am1 have been grown by the vapour diffusion method. these crystals diffract to beyond 2 a resolution and are suitable for x-ray crystallography. they belong to the orthorhombic space group p2(1)2(1)2(1) and have the following unit cell parameters: a = 66.79 a, b = 108.9 a, c = 188.9 a. one asymmetric unit contains an alpha 2 beta 2 tetramer of mdh and the location of the non-crystallographic 2-fold symmetry axis of ...19921447790
molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic acids in bacteria.the current knowledge on the structure and on the organization of polyhydroxyalkanoic acid (pha)-biosynthetic genes from a wide range of different bacteria, which rely on different pathways for biosynthesis of this storage polyesters, is provided. molecular data will be shown for genes of alcaligenes eutrophus, purple non-sulfur bacteria, such as rhodospirillum rubrum, purple sulfur bacteria, such as chromatium vinosum, pseudomonads belonging to rrna homology group i, such as pseudomonas aerugin ...19921476773
catheter infection caused by methylobacterium in immunocompromised hosts: report of three cases and review of the literature.three cases of catheter infection due to methylobacterium extorquens are reported. each patient had a history of acute leukemia and was immunocompromised; two had undergone bone marrow transplantation, and the third was receiving consolidation chemotherapy. all three patients survived after removal of the central venous catheter and antibiotic treatment. the clinical features of these cases are compared with those of the 12 previously reported cases of infection due to methylobacterium species.19921600002
cloning of a methanol-inducible moxf promoter and its analysis in moxb mutants of methylobacterium extorquens am1rif.in methylobacterium extorquens am1, gene encoding methanol dehydrogenase polypeptides are transcriptionally regulated in response to c1 compounds, including methanol (m. e. lidstrom and d. i. stirling, annu. rev. microbiol. 44:27-57, 1990). in order to study this regulation, a transcriptional fusion has been constructed between a beta-galactosidase reporter gene and a 1.55-kb xhoi-sali fragment of m. extorquens am1rif dna encoding the n terminus of the methanol dehydrogenase large subunit (moxf) ...19921624436
genetic organization of methylamine utilization genes from methylobacterium extorquens am1.an isolated 5.2-kb fragment of methylobacterium extorquens am1 dna was found to contain a gene cluster involved in methylamine utilization. analysis of polypeptides synthesized in an escherichia coli t7 expression system showed that five genes were present. two of the genes encoded the large and small subunits of methylamine dehydrogenase, and a third encoded amicyanin, the presumed electron acceptor for methylamine dehydrogenase, but the function of the other two genes is not known. the order o ...19911653226
isolation and characterization of the moxj, moxg, moxi, and moxr genes of paracoccus denitrificans: inactivation of moxj, moxg, and moxr and the resultant effect on methylotrophic growth.by using the moxf gene encoding the large fragment of methanol dehydrogenase as a probe, a downstream linked chromosomal fragment was isolated from a genomic bank of paracoccus denitrificans. the nucleotide sequence of the fragment was determined and revealed the 3' part of moxf, four additional open reading frames, and the 5' part of a sixth one. the organization and deduced amino acid sequences of the first three frames downstream from moxf were found to be largely homologous to the moxj, moxg ...19911657871
isolation, sequencing, and mutagenesis of the gene encoding cytochrome c553i of paracoccus denitrificans and characterization of the mutant strain.the periplasmically located cytochrome c553i of paracoccus denitrificans was purified from cells grown aerobically on choline as the carbon source. the purified protein was digested with trypsin to obtain several protein fragments. the n-terminal regions of these fragments were sequenced. on the basis of one of these sequences, a mix of 17-mer oligonucleotides was synthesized. by using this mix as a probe, the structural gene encoding cytochrome c553i (cycb) was isolated. the nucleotide sequence ...19911657873
purification and characterization of hydroxypyruvate reductase from the facultative methylotroph methylobacterium extorquens am1.hydroxypyruvate reductase was purified to homogeneity from the facultative methylotroph methylobacterium extorquens am1. it has a molecular mass of about 71 kda, and it consists of two identical subunits with a molecular mass of about 37 kda. this enzyme uses both nadh (km = 0.04 mm) and nadph (km = 0.06 mm) as cofactors, uses hydroxypyruvate (km = 0.1 mm) and glyoxylate (km = 1.5 mm) as the only substrates for the forward reaction, and carries out the reverse reaction with glycerate (km = 2.6 m ...19911657886
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 ...19901693657
cloning, mutagenesis, and physiological effect of a hydroxypyruvate reductase gene from methylobacterium extorquens am1.the gene encoding the serine cycle hydroxypyruvate reductase of methylobacterium extorquens am1 was isolated by using a synthetic oligonucleotide with a sequence based on a known n-terminal amino acid sequence. the cloned gene was inactivated by insertion of a kanamycin resistance gene, and recombination of this insertion derivative with the wild-type gene produced a serine cycle hydroxypyruvate reductase null mutant. this mutant had lost its ability to grow on c-1 compounds but retained the abi ...19921729225
nucleotide sequence of the amicyanin gene from methylobacterium extorquens am1.the gene for amicyanin from the methylotrophic bacterium, methylobacterium extorquens am1 was identified. it encodes a protein consisting of 119 amino acids with a molecular weight of 12,609 kda. the amino acid sequence shows the presence of a typical leader sequence and signal peptidase recognition site. two putative hairpin structures were found, one located directly behind the amicyanin gene and another located 50 bp upstream. the same sequence aaaatccc was found near the start codons for the ...19911802036
transformation of a methylotrophic bacterium, methylobacterium extorquens, with a broad-host-range plasmid by electroporation.electroporation was used to transform the methylotrophic bacterium methylobacterium extorquens with broad-host-range plasmid pla2917, which contains a gene specifying resistance to kanamycin. plasmid dna was introduced into m. extorquens in the presence of an electric pulse, and kanamycin-resistant transformants were obtained. these transformants harbored plasmid dna that was identical to plasmid pla2917. we examined several factors independently and found up to 8 x 10(3) transformants per micro ...19911809210
the amino acid sequence of rusticyanin isolated from thiobacillus ferrooxidans.the amino acid sequence of rusticyanin, a copper protein, purified from the iron-oxidizing bacterium thiobacillus ferrooxidans was determined. rusticyanin contained 154 amino acid residues in a single polypeptide chain and its molecular weight was calculated to be about 16,400 based on the amino acid sequence. the n-terminal sequence up to the 20th residue of the protein apparently resembled those of methylobacterium extorquens am1 amicyanin and poplar leaf plastocyanin rather than those of azur ...19911879547
the small-subunit polypeptide of methylamine dehydrogenase from methylobacterium extorquens am1 has an unusual leader sequence.the nucleotide sequence for the n-terminal region of the small subunit of methylamine dehydrogenase from methylobacterium extorquens am1 has revealed a leader sequence that is unusual in both its length and composition. gene fusions to lacz and phoa show that this leader sequence does not function in escherichia coli but does function in m. extorquens am1.19911885555
preliminary crystallographic study of a pseudoazurin from methylotrophic bacterium, methylobacterium extorquens am1.single crystals of pseudoazurin, one of the blue copper proteins produced by methylotrophic bacterium methylobacterium extorquens am1, have been obtained by the method of vapor diffusion with ammonium sulfate as a precipitant at ph 8.0. crystals belong to the orthorhombic system, space group p2(1)2(1)2(1), with unit cell dimensions of a = 52.619(4) a, b = 63.280(6) a, c = 35.133(4) a. the asymmetric unit includes one molecule of pseudoazurin (vm = 2.18 a3/dalton). the crystals are so stable agai ...19912002502
a new cofactor in a prokaryotic enzyme: tryptophan tryptophylquinone as the redox prosthetic group in methylamine dehydrogenase.methylamine dehydrogenase (madh), an alpha 2 beta 2 enzyme from numerous methylotrophic soil bacteria, contains a novel quinonoid redox prosthetic group that is covalently bound to its small beta subunit through two amino acyl residues. a comparison of the amino acid sequence deduced from the gene sequence of the small subunit for the enzyme from methylobacterium extorquens am1 with the published amino acid sequence obtained by the edman degradation method, allowed the identification of the amin ...19912028257
nucleotide sequence of the methylobacterium extorquens am1 moxf and moxj genes involved in methanol oxidation.the nucleotide sequence has been determined for two genes involved in methanol oxidation in the facultative methylotroph, methylobacterium extorquens am1. the two genes are moxf, encoding the 66-kda subunit of the methanol dehydrogenase and moxj, located immediately downstream from moxf, which encodes a 30-kda protein with unknown function. this information completes the sequence of the 5.86-kb xhoi-sali fragment containing the moxfjgi region in m. extorquens am1, and the structure of this gene ...19902116368
cloning and sequencing of the structural gene for the small subunit of methylamine dehydrogenase from methylobacterium extorquens am1: evidence for two tryptophan residues involved in the active center.in two independent clone libraries, clones were identified that hybridized with oligonucleotide probes based on n- or c-terminal polypeptide sequence of the small subunit of methylamine dehydrogenase from methylobacterium extorquens am1. plasmids from all clones had in common a 5.2 kb bam hi-hindiii dna fragment. a 0.57 kb sacii-bcli subfragment that hybridized to the oligonucleotide probes was sequenced. nucleotide sequence analysis coincided with polypeptide sequence data in the structural par ...19902121141
characterization of a novel soluble c-type cytochrome in a moxd mutant of methylobacterium extorquens am1.methylobacterium extorquens am1 contains a novel c-type cytochrome, called cytochrome c-553, previously thought to be a precursor of the electron acceptor (cytochrome cl) for methanol dehydrogenase. its amino acid composition and serological characteristics show that it has no structural relationship to cytochrome cl. it usually comprises less than 5% of the total c-type cytochromes. in a moxd mutant, which contains neither methanol dehydrogenase nor cytochrome cl, it comprises 30% of the solubl ...19902161900
the methanol-oxidizing system of methylobacterium extorquens am1 reconstituted with purified constituents.the electron transport system (with cytochrome aa3) coupled to the oxidation of methanol in methylobacterium extorquens am1 (former pseudomonas am1) was reconstituted with highly purified constituents of the system. a mixture of 2.7 microm methanol dehydrogenase, 3.2 microm cytochrome ch, and 71 nm cytochrome c oxidase (= cytochrome aa3) consumed oxygen at a lower rate in the presence of methanol, while its activity was enhanced 3-fold by the addition of 1.4 microm cytochrome cl (74 mol of o2 co ...19902168871
[clinical and bacteriological studies in four cases of pulmonary infection caused by protomonas extorquens].a novel bacterium, protomonas extorquens was isolated from sputum, pleural effusion and ascitis in four cases of pulmonary infection by buffered charcoal yeast extract agar (b-cye) which was generally used for legionella spp. three cases were so-called immunocompromised hosts (2 malignant diseases, 1 renal failure), and they died from underlying diseases. protomonas extorquens was newly named by komagata in 1984, which was characterized by production of pink pigment, growth in methanol medium an ...19902212763
biochemical and chemical characterization of pink-pigmented oxidative bacteria.the biochemical and chemical characteristics were determined for 156 clinical isolates of pink-pigmented bacteria that are similar to but distinct from methylobacterium extorquens (synonymous with pseudomonas mesophilica). these isolates were gram-negative, nonfermentative, usually nonvacuolated, coccoid rods; all grew at 35 degrees c and were catalase and urease positive; the majority grew on macconkey agar and were variable for oxidase production and motility. on the basis of oxidation of xylo ...19902332467
the poly-beta-hydroxybutyrate granule in vivo. a new insight based on nmr spectroscopy of whole cells.high resolution 13c nmr spectroscopy of live cells has been used to show that poly-beta-hydroxybutyrate (phb) is predominantly in a mobile state within the storage granules of alcaligenes eutrophus, methylobacterium extorquens, and methylobacterium am1. comparison of chemical and nmr analysis of phb indicates that about 70% of the polymer in a. eutrophus gives sharp observable resonances. temperature-dependent line widths and relaxation rates together with nuclear overhauser effect measurements ...19892492534
the second subunit of methanol dehydrogenase of methylobacterium extorquens am1.the nucleotide and deduced amino acid sequence of a novel small (beta) subunit of methanol dehydrogenase of methylobacterium extorquens am1 (previously pseudomonas am1) has been determined. work with the whole protein has shown that is has an alpha 2 beta 2 configuration.19892504152
the nucleotide sequence and deduced amino acid sequence of the cytochrome cl gene of methylobacterium extorquens am1, a novel class of c-type cytochrome.the nucleotide sequence and deduced amino acid sequence of the cytochrome cl of methylobacterium extorquens (pseudomonas am1; methylobacterium am1) shows that this cytochrome c is completely different, except for its haem-binding site, from all other cytochromes.19882851998
nucleotide sequences of 5s ribosomal rnas of protomonas extorquens, rhodopseudomonas palustris, rhodobacter capsulatus, and erythrobacter longus. 19863714477
distribution of the isopropylmalate pathway to leucine among diverse bacteria.alpha-isopropylmalate synthase and beta-isopropylmalate dehydrogenase activities were detected in extracts of the following organisms: chromatium d, rhodopseudomonas spheroides, hydrogenomonas h16, pseudomonas aeruginosa, pseudomonas fluorescens, vibrio extorquens, rhizobium japonicum, alcaligenes viscolactis, escherichia coli b, proteus vulgaris, aerobacter aerogenes, salmonella typhimurium, micrococcus sp., micrococcus lysodeikticus, bacillus polymyxa, bacillus subtilis, and nocardia opaca. th ...19744829932
studies on the production of pink pigment in pseudomonas extorquens ncib 9399 growing in continuous culture. 19744846740
microbial growth on c1 compounds. the role of folat in the metabolism of pseudomonas am1.1. the growth of pseudomonas am1 is much more sensitive to inhibition by sulphanilamide when methanol, rather than succinate, acts as the sole carbon and energy source; a sulphanilamide concentration of 1mm, which causes almost complete inhibition of growth on methanol, has little effect in a succinate medium. 2. similar results have been obtained with sulphadiazine and sulphathiazole. sulphanilic acid has little effect. 3. a similar differential sensitivity to sulphanilamide is shown by protami ...19664957628
microbial growth on oxalate by a route not involving glyoxylate carboligase.1. the metabolism of oxalate by the pink-pigmented organisms, pseudomonas am1, pseudomonas am2, protaminobacter ruber and pseudomonas extorquens has been compared with that of the non-pigmented pseudomonas oxalaticus. 2. during growth on oxalate, all the organisms contain oxalyl-coa decarboxylase, formate dehydrogenase and oxalyl-coa reductase. this is consistent with oxidation of oxalate to carbon dioxide taking place via oxalyl-coa, formyl-coa and formate as intermediates, and also reduction o ...19705472155
culture of vibrio extorquens from severe, chronic skin ulcers in a puerto rican woman.a 48-year-old puerto rican woman developed extensive ulcers on her buttocks, right arm, and thighs over a 3 1/2-year period. the lesions began as small, subcutaneous nodules which subsequently ulcerated and expanded up to 19 cm in diameter. biopsy of both ulcerated and nonulcerated lesions showed acid-fast bacilli. culture of both types of lesions grew vibrio extorquens, a partially acid-fast methanolophilic organism not previously associated with disease in humans. the patient developed aggluti ...19836886116
identification and nucleotide sequences of mxaa, mxac, mxak, mxal, and mxad genes from methylobacterium extorquens am1.the dna sequence for a 4.4-kb hindiii-xhoi methylobacterium extorquens am1 dna fragment that is known to contain three genes (mxaakl) involved in incorporation of calcium into methanol dehydrogenase (i. w. richardson and c. anthony, biochem. j. 287:709-7115, 1992) was determined. five complete open reading frames and two partial open reading frames were found, suggesting that this region contains previously unidentified genes. a combination of sequence analysis, mutant complementation data, and ...19957592474
mutational analysis of mau genes involved in methylamine metabolism in paracoccus denitrificans.a chromosomal fragment containing dna downstream from mauc was isolated from paracoccus denitrificans. sequence analysis of this fragment revealed the presence of four open reading frames, all transcribed in the same direction. the products of the putative genes were found to be highly similar to mauj, maug, maum and maun of methylobacterium extorquens am1. using these four mau genes, 11 mau genes have been cloned from p. denitrificans to date. the gene order is maurfbedacjgmn, which is similar ...19957601147
the active site of methanol dehydrogenase contains a disulphide bridge between adjacent cysteine residues.adjacent cysteine residues can only form disulphide bridges in a distorted structure containing a cis-peptide link. such bridges are extremely uncommon, identified so far in the acetyl choline receptor alone where the structure of the bridge is undetermined. here we present the first molecular description of a disulphide bridge of this type in the quinoprotein methanol dehydrogenase from methylobacterium extorquens. we show that this structure occurs in close proximity to the pyrrolo-quinoline q ...19947656012
the refined structure of the quinoprotein methanol dehydrogenase from methylobacterium extorquens at 1.94 a.methanol dehydrogenase (mdh) is a bacterial periplasmic quinoprotein; it has pyrrolo-quinoline quinone (pqq) as its prosthetic group, requires ca2+ for activity and uses cytochrome cl as its electron acceptor. low-resolution structures of mdh have already been determined.19957735834
the role of the novel disulphide ring in the active site of the quinoprotein methanol dehydrogenase from methylobacterium extorquens.all cysteines in methanol dehydrogenase (mdh) from methylobacterium extorquens are involved in intra-subunit disulphide bridge formation. one of these is between adjacent cysteine residues which form a novel ring structure in the active site. it is readily reduced, the reduced enzyme being inactive in electron transfer to cytochrome cl. the inactivation is not a result of major structural change or to modification of the prosthetic group pyrrolo-quinoline quinone (pqq). the reduced enzyme appear ...19957741704
cloning and characterization of the methylobacterium extorquens polyhydroxyalkanoic-acid-synthase structural gene.a cosmid gene bank of partially ecori-digested genomic dna from methylobacterium extorquens ibt no. 6 was screened for dna fragments restoring polyhydroxyalkanoic-acid (pha) accumulation in the pha-negative mutant alkaligenes eutrophus h16 phb-4. the m. extorquens pha-synthase structural gene phacmex was mapped on a 23-kbp ecori fragment by complementation studies, by hybridization experiments with heterologous dna probes from a. eutrophus h16 encoding for phaa, phab and phac and by nucleic acid ...19937763712
the structure of the quinoprotein alcohol dehydrogenase of acetobacter aceti modelled on that of methanol dehydrogenase from methylobacterium extorquens.the 1.94 a structure of methanol dehydrogenase has been used to provide a model structure for part of a membrane quinohaemoprotein alcohol dehydrogenase. the basic superbarrel structure and the active-site region are retained, indicating essentially similar mechanisms of action, but there are considerable differences in the external loops, particularly those involved in formation of the shallow funnel leading to the active site.19957772016
identification of a promoter region for mxaf (moxf) from the type i methanotroph, methylobacter albus bg8.a fragment of methylobacter albus bg8 dna containing mxaf (moxf), the gene encoding the alpha subunit of methanol dehydrogenase, was previously cloned using a fragment of mxaf from methylobacterium extorquens am1 as a probe (stephens et al., j. bacteriol. (1988) 170, 2063-2069). in this study we identified the 5' portion of mxaf of m. albus bg8 and sequenced a 1.7-kb region containing the 5' portion of mxaf and 1.5 kb of upstream dna. the deduced n-terminal amino acid sequence of mxaf was found ...19947926691
genetics of the serine cycle in methylobacterium extorquens am1: cloning, sequence, mutation, and physiological effect of glya, the gene for serine hydroxymethyltransferase.the gene (glya) of methylobacterium extorquens am1 encoding serine hydroxymethyltransferase (shmt), one of the key enzymes of the serine cycle for c1 assimilation, was isolated by using a synthetic oligonucleotide with a sequence based on amino acid sequence conserved in shmts from different sources. the amino acid sequence deduced from the gene revealed high similarity to those of known shmts. the cloned gene was inactivated by insertion of a kanamycin resistance gene, and recombination of this ...19947961431
genetics of the serine cycle in methylobacterium extorquens am1: identification, sequence, and mutation of three new genes involved in c1 assimilation, orf4, mtka, and mtkb.in a recent paper we reported the sequence of the beginning of a serine cycle gene cluster on the methylobacterium extorquens am1 chromosome, containing the genes encoding serine glyoxylate aminotransferase (sgaa), hydroxypyruvate reductase (hpra), and 5,10-methylenetetrahydrofolate dehydrogenase (mtda) (l. v. chistoserdova and m. e. lidstrom j. bacteriol. 176:1957-1968, 1994). here we present the sequence of the adjacent downstream region containing three full and one partial open reading frame ...19947961516
transcriptional analysis of pqqd and study of the regulation of pyrroloquinoline quinone biosynthesis in methylobacterium extorquens am1.methanol dehydrogenase, the enzyme that oxidizes methanol to formaldehyde in gram-negative methylotrophs, contains the prosthetic group pyrroloquinoline quinone (pqq). to begin to analyze how the synthesis of pqq is coordinated with the production of other methanol dehydrogenase components, the transcription of one of the key pqq synthesis genes has been studied. this gene (pqqd) encodes a 29-amino-acid peptide that is thought to be the precursor for pqq biosynthesis. a unique transcription star ...19958002620
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 ...19948021187
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 ...19948021188
x-ray structure of pqq-dependent methanol dehydrogenase.the three-dimensional structure of the pqq-dependent quinoprotein, methanol dehydrogenase from methylobacterium extorquens am1, has been determined at 3a resolution. the a2b2 tetrameric enzyme has a large a-chain of almost spherical form with a chain fold in which eight 4-stranded antiparallel b-sheets segments are arranged radially around a pseudo 8-fold molecular symmetry axis. the much smaller b-chain is surprisingly not globular, but has an extended conformation running across the surface of ...19948032156
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 ...19948055954
genetics of methane and methanol oxidation in gram-negative methylotrophic bacteria.within the past few years, considerable progress has been made in the understanding of the molecular genetics of methane and methanol oxidation. in order to summarize this progress and to illustrate the important genetic methods employed, this review will focus on several well-studied organisms. these organisms include the gram-negative faculative methylotrophs methylobacterium extorquens, methylobacterium organophilum and paracoccus denitrificans. in addition, the obligate methanotrophs methylo ...19938092853
isolation, phenotypic characterization, and complementation analysis of mutants of methylobacterium extorquens am1 unable to synthesize pyrroloquinoline quinone and sequences of pqqd, pqqg, and pqqc.aerobic gram-negative methylotrophs oxidize methanol to formaldehyde by using a methanol dehydrogenase that has pyrroloquinoline quinone (pqq) as a prosthetic group. seventy-two mutants which are unable to grow on methanol unless the growth medium is supplemented with pqq have been isolated in the facultative methanol utilizer methylobacterium extorquens am1. in addition, 12 previously isolated methanol oxidation mutants of m. extorquens am1 were shown to be able to grow on methanol in the prese ...19948132470
genetics of the serine cycle in methylobacterium extorquens am1: identification of sgaa and mtda and sequences of sgaa, hpra, and mtda.in a previous paper, we reported identification of the 5' part of hpra of methylobacterium extorquens am1, which encodes the serine cycle enzyme hydroxypyruvate reductase (l. v. chistoserdova and m. e. lidstrom, j. bacteriol. 174:71-77, 1992). here we present the complete sequence of hpra and partial sequence of genes adjacent to hpra. upstream of hpra, the 3' part of an open reading frame was discovered, separated from hpra by 263 bp. this open reading frame was identified as the gene encoding ...19948144463
mutants of methylobacterium extorquens and paracoccus denitrificans deficient in c-type cytochrome biogenesis synthesise the methylamine-dehydrogenase polypeptides but cannot assemble the tryptophan-tryptophylquinone group.five mutants of methylobacterium extorquens and four mutants of paracoccus denitrificans that have a general defect in c-type cytochrome synthesis also failed to assemble an active methylamine dehydrogenase. in all cases methanol dehydrogenase, another periplasmic enzyme, was fully active. all nine mutant strains accumulated both the heavy and light subunits of methylamine dehydrogenase to essentially wild-type levels. in all nine mutants, the heavy-subunit and light-subunit polypeptides were pr ...19938269962
a novel quinoprotein methanol dehydrogenase containing an additional 32-kilodalton peptide purified from acetobacter methanolicus: identification of the peptide as a moxj product.acetobacter methanolicus is a unique acetic acid bacterium which has a methanol oxidase respiratory chain in addition to an ethanol oxidase respiratory chain. in this study, two different forms of methanol dehydrogenase (type i and ii mdhs) were purified from a. methanolicus grown on methanol. type i mdh was more basic (pi of 8.0) and smaller (m(r) of 148k) than type ii mdh (pi of 6.7 and m(r) of 177k). type i mdh consisted of alpha and beta subunits of 62 and 10 kda, which has the same alpha 2 ...19938389187
identification and growth characteristics of pink pigmented oxidative bacteria, methylobacterium mesophilicum and biovars isolated from chlorinated and raw water supplies.pink pigmented bacteria were isolated from a blood bank water purification unit, a municipal town water supply (tap water), and an island (untreated) ground water source. a total of thirteen strains including two reference strains of pink pigmented bacteria were compared in a numerical phenotypic study using 119 binary characters. three clusters were derived, one major cluster of eleven strains was subdivided into two sub-clusters on the basis of methanol utilization. five strains were facultati ...19938469180
genetics of serine pathway enzymes in methylobacterium extorquens am1: phosphoenolpyruvate carboxylase and malyl coenzyme a lyase.methylobacterium extorquens am1 is a facultative methylotrophic bacterium that uses the serine pathway for formaldehyde incorporation as its assimilation pathway during growth on one-carbon compounds. a dna region from m. extorquens am1 previously shown to contain genes for the serine pathway enzymes malyl coenzyme a (coa) lyase and hydroxypyruvate reductase has been characterized in more detail. insertion mutagenesis revealed an additional region required for growth on one-carbon compounds, and ...19938509332
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 ...19938515233
tn5-directed cloning of pqq genes from pseudomonas fluorescens cha0: mutational inactivation of the genes results in overproduction of the antibiotic pyoluteorin.pseudomonas fluorescens cha0 produces several secondary metabolites, e.g., the antibiotics pyoluteorin (plt) and 2,4-diacetylphloroglucinol (phl), which are important for the suppression of root diseases caused by soil-borne fungal pathogens. a tn5 insertion mutant of strain cha0, cha625, does not produce phl, shows enhanced plt production on malt agar, and has lost part of the ability to suppress black root rot in tobacco plants and take-all in wheat. we used a rapid, two-step cloning-out proce ...19958526497
methanol oxidation mutants in methylobacterium extorquens am1: identification of new genetic complementation groups.two-hundred-and-eight new methylobacterium extorquens am1 methanol oxidation (mox) mutants were isolated and placed into complementation groups. complementation analyses identified new mox groups in the mxb and mxc loci and at a new locus, mxd. thirty-seven mutants at the mxb locus were divided into mxbm and mxbd complementation groups on the basis of their complementation pattern. twenty-nine mutants at the mxc locus fell into three complementation groups, mxcb, mxcq and mxce. the direction of ...19958535526
the mxaakl genes of methylobacter albus bg8.the facultative methanol utilizer methylobacterium extorquens am1 contains at least three genes (mxaa, k and l) that encode functions involved in providing calcium to the holoenzyme of methanol dehydrogenase, the enzyme that oxidizes methanol to formaldehyde in this strain. methane-utilizing bacteria (methanotrophs) also contain methanol dehydrogenase, and evidence suggests that similar methanol oxidation (mox) functions may be present in some of these strains. dna fragments from methylobacteriu ...19958535527
structure of the quinoprotein glucose dehydrogenase of escherichia coli modelled on that of methanol dehydrogenase from methylobacterium extorquens.the structure of methanol dehydrogenase (mdh) at 0.194 nm (1.94 a) has been used to provide a model structure for part of a membrane quinoprotein glucose dehydrogenase (gdh). the basic superbarrel structure is retained, along with the tryptophan-docking motifs. the active-site regions are similar, but there are important differences, the most important being that gdh lacks the novel disulphide ring structure formed from adjacent cysteines in mdh; in gdh the equivalent region is occupied by his-2 ...19958554505
primary structure and properties of the formyltransferase from the mesophilic methanosarcina barkeri: comparison with the enzymes from thermophilic and hyperthermophilic methanogens.the ftr gene encoding formylmethanofuran: tetrahydromethanopterin formyltransferase (ftr) from methanosarcina barkeri was cloned, sequenced, and functionally expressed in escherichia coli. the overproduced enzyme was purified eightfold to apparent homogeneity, and its catalytic properties were determined. the primary structure and the hydropathic character of the formyltransferase from methanosarcina barkeri were compared with those of the enzymes from methanobacterium thermoautotrophicum, metha ...19968593103
characterization and nucleotide sequence of pqqe and pqqf in methylobacterium extorquens am1.methylobacterium extorquens am1 pqqef are genes required for synthesis of pyrroloquinoline quinone (pqq). the nucleotide sequence of these genes indicates pqqe belongs to an endopeptidase family, including pqqf of klebsiella pneumoniae, and m. extorquens am1 pqqf has low identity with the same endopeptidase family. m. extorquens am1 pqqe complemented a k. pneumoniae pqqf mutant.19968606199
molecular characterization of a chromosomal region involved in the oxidation of acetyl-coa to glyoxylate in the isocitrate-lyase-negative methylotroph methylobacterium extorquens am1.a region on the methylobacterium extorquens am1 chromosome previously shown to complement a chemically induced mutant (pct48) unable to convert acetyl-coa into glyoxylate was characterized in detail in order to identify the gene(s) involved in the unknown pathway for acetyl-coa oxidation. six complete and two partial orfs were identified by sequencing. sequence comparisons suggested these might code for, respectively, a dehydrogenase of unknown specificity, a polypeptide of at least 15 kda with ...19968704985
a protein having similarity with methylmalonyl-coa mutase is required for the assimilation of methanol and ethanol by methylobacterium extorquens am1.a 4.0 kb region of methylobacterium extorquens am1 dna which complements three mutants unable to convert acetyl-coa to glyoxylate (and therefore defective in the assimilation of methanol and ethanol) has been isolated and sequenced. it contains two orfs and the 3'-end of a third one. the mutations in all three mutants mapped within the first orf, which was designated meaa; it encodes a protein having similarity with methylmalonyl-coa mutase. however, methylmalonyl-coa mutase was measured in extr ...19968868443
cloning and expression of the gene for serine-glyoxylate aminotransferase from an obligate methylotroph hyphomicrobium methylovorum gm2.the gene encoding serine-glyoxylate aminotransferase, one of key enzymes for the assimilation of one-carbon compounds in methylotrophs, and its flanking regions were isolated from an obligate methylotrophic bacterium, hyphomicrobium methylovorum gm2. nucleotide sequencing of the recombinant plasmids revealed that the serine-glyoxylate aminotransferase gene encodes a 405-amino-acid protein with a calculated molecular mass of 43880 da. the amino acid sequence of the enzyme showed identity to the s ...19968898880
reconstitution of the quinoprotein methanol dehydrogenase from inactive ca(2+)-free enzyme with ca2+, sr2+ or ba2+.the reconstitution of active holoenzyme containing calcium from inactive calcium-free methanol dehydrogenase, isolated from a moxa mutant of methylobacterium extorquens, has a ph optimum of about ph 10, with a well defined pk for the process at ph 9.3. two ca2+ ions were irreversibly incorporated per alpha 2 beta 2 tetramer. calcium could be replaced in the incorporation process by strontium or barium, the affinities for these ions being similar to that for ca2+. arrhenius plots for measurement ...19968920988
the methanol oxidation genes mxafjgir (s) ackld in methylobacterium extorquens.mxaj is a protein of unknown function encoded by mxaj in the mxafjgi operon. we have constructed a mxaj mutant of m. extorquens with a deletion which does not affect transcription of downstream genes. it contained cytochrome cl (mxag), but neither subunit of methanol dehydrogenase (mxaf and mxai). mxaj is probably involved in processing this enzyme. we have sequenced the region between mxafjgi and five other methanol oxidation genes, mxaackld; it includes one open reading frame (mxar) and a poss ...19978997703
sequence analysis of pqq genes required for biosynthesis of pyrroloquinoline quinone in methylobacterium extorquens am1 and the purification of a biosynthetic intermediate.methylobacterium extorquens am1 produces pyrroloquinoline quinone (pqq), the prosthetic group of methanol dehydrogenase. two genes clusters have been shown to be required for pqq biosynthesis in this micro-organism and complementation analysis has identified seven pqq genes, pqqdgcba and pqqef. the dna sequence of pqqdgc' was reported previously. this paper reports the sequence of the genomic region corresponding to pqqc'ba. for consistency, the nomenclature of pqq genes in klebsiella pneumoniae ...19979043136
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. ...19979090108
analysis of the pha granule-associated proteins ga20 and ga11 in methylobacterium extorquens and methylobacterium rhodesianum.electrophoretic analysis of the proteins bound to poly(3-hydroxybutyric acid), phb-, granules in methylobacterium extorquens, m. rhodesianum as well as the phb-leaky mutants mu 1 and mu 11, which were isolated from the latter, resulted in two dominant low-molecular weight proteins, which were referred to as ga11 and ga20. after purification of these proteins antibodies against the ga11 and ga20 protein of m. extorquens were obtained. both proteins bound to the surface of phb granules as revealed ...19979090123
purification and characterization of citrate synthase from methylobacterium extorquens--a methylotrophic producer of polyhydroxybutyrate.citrate synthase (citrate oxaloacetate-lyase, coa-acetylating; ec 4.1.3.7, cs) was isolated and purified to homogeneity from a methylotrophic producer of polyhydroxybutyrate (phb), methylobacterium extorquens 15. the purification procedure includes streptomycin sulfate treatment of cell-free extract, ammonium sulfate fractionation, two steps of hydrophobic chromatography, and ion-exchange chromatography. the specific activity of the final enzyme preparation was 24 u/mg protein. the enzyme has ap ...19979113733
sequence and functional analysis of an escherichia coli dna fragment able to complement pqqe and pqqf mutants from methylobacterium organophilum.a 7361 kb fragment of e coli chromosomal dna able to complement pqqe and pqqf mutants of methylobacterium organophilum has been sequenced. five open reading frames (orf) have been identified. four orfs (102, 103, 106 and 107), belong to a single transcription unit. they are separated by a transcription termination site from a fifth orf (orf109). polypeptides of 28, 85 and 82 kda encoded by orfs 102, 103 and 106 respectively were visualised in maxi-cell experiments. both orf106 and orf107 are req ...19969116051
erratum to "the methanol oxidation genes mxafjgir (s) ackld in methylobacterium extorquens" [fems microbiol. lett. 146 (1997) 31-38]. 19979163922
molecular and mutational analysis of a dna region separating two methylotrophy gene clusters in methylobacterium extorquens am1.a region of 14.2 kb has been analysed that is a part of a locus on the methylobacterium extorquens am1 chromosome containing a number of genes involved in one-carbon (c1) metabolism, including serine cycle genes, pqq genes, regulatory methanol oxidation genes and the gene for n5,n10-methylene tetrahydrofolate dehydrogenase (mtda). fifteen new orfs have been identified within the new region, and their sequences suggest that they encode the following polypeptides: the c-terminal part of phosphoeno ...19979168622
molecular analysis of mxbd and mxbm, a putative sensor-regulator pair required for oxidation of methanol in methylobacterium extorquens am1.five genes are thought to be required for transcription of methanol oxidation genes in methylobacterium strains. these putative regulatory genes include mxcqe, which encode a putative sensor-regulator pair, and mxbdm and mxab, whose functions are less well-understood. in this study, mxbdm in methylobacterium extorquens am1 were shown to be required for expression of a xyle transcriptional fusion to the structural gene for the large subunit of methanol dehydrogenase (mxaf), confirming the role of ...19979168623
organization of methylamine utilization genes (mau) in 'methylobacillus flagellatum ' kt and analysis of mau mutants.the organization of genes involved in utilization of methylamine (mau genes) was studied in the obligate methylotroph 'methylobacillus flagellatum' kt. nine open reading frames were identified as corresponding to the genes maufbedaglmn. in addition, an open reading frame (orf-1 encoding a polypeptide with unknown function was identified upstream of the mau gene cluster. subclones of the 'm. flagellatum' kt gene cluster were used for complementation of a series of chemically induced mau mutants o ...19979202457
identification and mutation of a gene required for glycerate kinase activity from a facultative methylotroph, methylobacterium extorquens am1.a gene (gcka) responsible for the activity of glycerate kinase has been identified within a chromosomal fragment of the serine cycle methylotroph methylobacterium extorquens am1. a mutation in gcka leads to a specific c1-negative phenotype. the polypeptide sequence derived from gcka showed high similarity to a product of ttud essential for tartrate metabolism in agrobacterium vitis. our data suggest that gcka and ttud might be structural genes for glycerate kinase and that the serine cycle and t ...19979244287
a novel alternate anaplerotic pathway to the glyoxylate cycle in streptomycetes.ccr encoding crotonyl coenzyme a (coa) reductase (ccr), which catalyzes the conversion of crotonyl-coa to butyryl-coa in the presence of nadph, was previously cloned from streptomyces collinus. we now report that a complete open reading frame, designated meaa, is located downstream from ccr. the predicted gene product showed 35% identity with methylmalonyl-coa mutases from various sources. in addition, the predicted amino acid sequences of s. collinus ccr and meaa exhibit strong similarity to th ...19979260959
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 ...19979311140
purification and properties of methanol dehydrogenase from methylocystis sp. gb 25.methanol dehydrogenase (mdh) from methylocystis sp. gb 25, which belongs to the group ii of methanotrophic bacteria, is able to catalyse the oxidation of methanol to formate directly. the enzyme was purified 20-fold by a 5 step procedure to electrophoretic homogeneity. after cell disruption by french press, about 95% of mdh-activity was found in the soluble fraction. the relative molecular mass of the native enzyme has been estimated to be 122 kda by gel filtration and 115 kda by the method of h ...19979323867
heterologous expression of heterotrophic nitrification genes.paracoccus denitrificans is a heterotrophic organism capable of oxidizing ammonia to nitrite during growth on an organic carbon and energy source. this pathway, termed heterotrophic nitrification, requires the concerted action of an ammonia monooxygenase (amo) and hydroxylamine oxidase (hao). the genes required for heterotrophic nitrification have been isolated by introducing a pa. denitrificans genomic library into pseudomonas putida and screening for the accumulation of nitrite. in contrast to ...19979421902
an rna polymerase preparation from methylobacterium extorquens am1 capable of transcribing from a methylotrophic promoter.rna polymerase (rnap) was purified from methylobacterium extorquens am1 cells grown on methanol or on succinate. the beta, beta', alpha and omega subunits were approximately the same size as those of escherichia coli, and the identity of the omega subunit was confirmed by n-terminal sequence analysis. n-terminal sequence analysis suggested that two other polypeptides in the purified rnap preparation might be sigma factors, a 40 kda polypeptide that shared identity with sigma 32 homologues, and a ...19989467910
pqqa is not required for biosynthesis of pyrroloquinoline quinone in methylobacterium extorquens am1.methylobacterium extorquens am1 is a facultative methylotroph that oxidizes methanol via the pyrroloquinoline quinone (pqq)-linked enzyme methanol dehydrogenase. in m. extorquens am1 and other pqq-synthesizing bacteria, several genes are involved in the synthesis of pqq and one of these, pqqa, has been proposed to encode a peptide precursor of pqq. in other pqq-synthesizing bacteria, pqqa is required for pqq production. in this study, it is shown that both deletion and insertion mutants of pqqa ...19989467911
sequence and characterization of mxab, a response regulator involved in regulation of methanol oxidation, and of mxaw, a methanol-regulated gene in methylobacterium extorquens am1.in the facultative serine cycle methylotroph methylobacterium extorquens am1, mxab is required for regulation of methanol oxidation and is located at the end of a large cluster of methylotrophy genes that begins with mxaf. the sequence of mxab has been obtained and indicates that the gene product is a member of the response regulator family. none of the open reading frames near mxab showed sequence identity to sensor kinases. complementation studies suggest a promoter may be located adjacent to ...19989495022
evolutionary relationship between chlorocatechol catabolic enzymes from rhodococcus opacus 1cp and their counterparts in proteobacteria: sequence divergence and functional convergence.biochemical investigations of the muconate and chloromuconate cycloisomerases from the chlorophenol-utilizing strain rhodococcus opacus (erythropolis) 1cp had previously indicated that the chlorocatechol catabolic pathway of this strain may have developed independently from the corresponding pathways of proteobacteria. to test this hypothesis, we cloned the chlorocatechol catabolic gene cluster of strain 1cp by using pcr with primers derived from sequences of n termini and peptides of purified c ...19989495745
bacterial community dynamics during start-up of a trickle-bed bioreactor degrading aromatic compounds.this study was performed with a laboratory-scale fixed-bed bioreactor degrading a mixture of aromatic compounds (solvesso100). the starter culture for the bioreactor was prepared in a fermentor with a wastewater sample of a care painting facility as the inoculum and solvesso100 as the sole carbon source. the bacterial community dynamics in the fermentor and the bioreactor were examined by a conventional isolation procedure and in situ hybridization with fluorescently labeled rrna-targeted oligon ...19989501433
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 ...19989613842
analysis of genes involved in biosynthesis of coronafacic acid, the polyketide component of the phytotoxin coronatine.coronafacic acid (cfa) is the polyketide component of coronatine (cor), a phytotoxin produced by the plant-pathogenic bacterium pseudomonas syringae. the genes involved in cfa biosynthesis are encoded by a single transcript which encompasses 19 kb of the cor gene cluster. in the present study, the nucleotide sequence was determined for a 4-kb region located at the 3' end of the cfa biosynthetic gene cluster. three open reading frames were identified and designated cfa8, cfa9, and tnp1; the predi ...19989642184
c1 transfer enzymes and coenzymes linking methylotrophic bacteria and methanogenic archaea.methanogenic and sulfate-reducing archaea are considered to have an energy metabolism involving c1 transfer coenzymes and enzymes unique for this group of strictly anaerobic microorganisms. an aerobic methylotrophic bacterium, methylobacterium extorquens am1, was found to contain a cluster of genes that are predicted to encode some of these enzymes and was shown to contain two of the enzyme activities and one of the methanogenic coenzymes. insertion mutants were all unable to grow on c1 compound ...19989651254
[ecological consequences of radioactive pollution for soil bacteria within the 10-km region around the chernobyl atomic energy station].the diversity of aerobic chemoorganotrophic (capable of growing on nutrient agar) bacteria in radioactive soil (0.3-17.0 microci/kg soil) sampled in the 10-km zone around the chernobyl nuclear power plant (cnpp) was found to be lower than that observed in control, uncontaminated soil with a radioactivity of 0.002-0.006 microci/kg soil. all the radioactive soil samples contained the bacteria bacillus cereus and methylobacterium extorquens or m. mesophillicum, which exhibited a high tolerance to 0 ...19989662700
genetic analysis of comamonas acidovorans polyhydroxyalkanoate synthase and factors affecting the incorporation of 4-hydroxybutyrate monomer.the polyhydroxyalkanoate (pha) synthase gene of comamonas acidovorans ds-17 (phacca) was cloned by using the synthase gene of alcaligenes eutrophus as a heterologous hybridization probe. complete sequencing of a 4.0-kbp smai-hindiii (sh40) subfragment revealed the presence of a 1,893-bp pha synthase coding region which was followed by a 1,182-bp beta-ketothiolase gene (phaaca). both the translated products of these genes showed significant identity, 51.1 and 74.2%, respectively, to the primary s ...19989726894
construction of insertion and deletion mxa mutants of methylobacterium extorquens am1 by electroporation.methylobacterium extorquens am1 is a pink-pigmented facultative methylotroph which is widely used for analyzing pathways of c1 metabolism with biochemical and molecular biological techniques. to facilitate this approach, we have applied a new method to construct insertion or disruption mutants with drug resistance genes by electroporation. by using this method, mutants were obtained in four genes present in the mxa methylotrophy gene cluster for which the functions were unknown, mxar, mxas, mxac ...19989741078
crystallographic and spectroscopic studies of native, aminoquinol, and monovalent cation-bound forms of methylamine dehydrogenase from methylobacterium extorquens am1.various monovalent cations influence the enzymatic activity and the spectroscopic properties of methylamine dehydrogenase (madh). here, we report the structure determination of this tryptophan tryptophylquinone-containing enzyme from methylobacterium extorquens am1 by high resolution x-ray crystallography (1.75 a). this first madh crystal structure at low ionic strength is compared with the high resolution structure of the related madh from paracoccus denitrificans recently reported. we also des ...19989748238
strain imb-1, a novel bacterium for the removal of methyl bromide in fumigated agricultural soils.a facultatively methylotrophic bacterium, strain imb-1, that has been isolated from agricultural soil grows on methyl bromide (mebr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. phylogenetic analysis of its 16s rrna gene sequence indicates that strain imb-1 classes in the alpha subgroup of the class proteobacteria and is closely related to members of the genus rhizobium. the ability of strain imb-1 to oxidize mebr to co2 is constitutive in ...19989750123
c-type cytochromes and manganese oxidation in pseudomonas putida mnb1.pseudomonas putida mnb1 is an isolate from an mn oxide-encrusted pipeline that can oxidize mn(ii) to mn oxides. we used transposon mutagenesis to construct mutants of strain mnb1 that are unable to oxidize manganese, and we characterized some of these mutants. the mutants were divided into three groups: mutants defective in the biogenesis of c-type cytochromes, mutants defective in genes that encode key enzymes of the tricarboxylic acid cycle, and mutants defective in the biosynthesis of tryptop ...19989758766
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