| factors affecting the stability of methanol dehydrogenase from paracoccus denitrificans. | methanol dehydrogenase from paracoccus denitrificans was purified to homogeneity in two steps from the periplasmic fraction of methanol-grown cells. the enzyme was composed of subunits of m(r) 67,000 and 12,000, and non-covalently bound pyrroloquinoline quinone. it exhibited a ph optimum at ph values of 9.0 and above. it was not stable at ph greater than 9.0, but exhibited little loss of activity after prolonged incubation at ph values as low as 4.5. methyl dehydrogenase was relatively stable to ... | 1992 | 1325939 |
| purification of cytochrome c oxidase by lysine-affinity chromatography. | a method for the purification of cytochrome c oxidase that is based on the affinity of this enzyme for polycations such as poly-l-lysine is described. when detergent extracts of bovine cardiac mitochondria were applied to either a poly-l-lysine-agarose or a lysine-sepharose column at low ionic strength, cytochrome c oxidase was found to adhere tightly, whereas the bulk of the proteins were eluted by washing with the same buffer. the cytochrome c oxidase was eluted by application of a linear pota ... | 1992 | 1330132 |
| a comparative epr investigation of the multicopper proteins nitrous-oxide reductase and cytochrome c oxidase. | the multicopper proteins, nitrous-oxide reductase (n2or) and cytochrome c oxidase (cox), were investigated by epr spectroscopy at microwave frequencies 2.4-35 ghz. our results support a cu-cu interaction in cox and n2or. at least 10 lines in the 2.7-ghz, 12 lines in the 4.6-ghz and 14 lines in the 9.2 ghz spectra were resolved for n2or. eight copper lines at 2.7 ghz, about nine lines at 4.6 ghz and about six lines at 9.2 ghz were resolved for cox. simulations of the epr spectra were consistent w ... | 1992 | 1330560 |
| 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 |
| relationship between cardiolipin content and cytochrome c oxidase activity of cytochrome aa3 in paracoccus denitrificans. | using cultivation at different oxygen tensions, the molar ratio of cardiolipin to haem a in cells of paracoccus denitrificans was varied systematically from 30 to 300. the molecular activity of cytochrome aa3 (with n, n, n', n'-tetramethyl-p-phenylenediamine as substrate) remained unchanged in this interval, this ruling out any regulatory effect of physiological cardiolipin levels on the terminal oxidase. titration of anaerobically grown cells with cyanide indicated the presence of cytochrome aa ... | 1992 | 1332723 |
| epr studies of cytochrome aa3 from sulfolobus acidocaldarius. evidence for a binuclear center in archaebacterial terminal oxidase. | the purified cytochrome aa3-type oxidase from sulfolobus acidocaldarius (dsm 639) consists of a single subunit, containing one low-spin and one high-spin a-type hemes and copper [anemüller, s. and schäfer, g. (1990) eur. j. biochem. 191, 297-305]. the enzyme metal centers were investigated by electron paramagnetic resonance spectroscopy (epr), coupled to redox potentiometry. the low-spin heme epr signal has the following g-values: gz = 3.02, gy = 2.23 and gx = 1.45 and the high-spin heme exhibit ... | 1992 | 1332857 |
| cytochrome aa3 of rhodobacter sphaeroides as a model for mitochondrial cytochrome c oxidase. the coxii/coxiii operon codes for structural and assembly proteins homologous to those in yeast. | the coxii/coxiii operon of rhodobacter sphaeroides cytochrome c oxidase has been sequenced and characterized by insertional inactivation/complementation analysis. the organization of the genes in this locus (coxii.orf1.orf3.coxiii) is the same as that of the equivalent operon of paracoccus denitrificans (ctac.ctab.ctag.ctae), but unlike that of other bacteria whose cytochrome oxidase genes have been characterized so far. the predicted amino acid sequence homology with eukaryotic oxidases is also ... | 1992 | 1332950 |
| electronic and vibrational spectroscopy of the cytochrome c:cytochrome c oxidase complexes from bovine and paracoccus denitrificans. | the 1:1 complex between horse heart cytochrome c and bovine cytochrome c oxidase, and between yeast cytochrome c and paracoccus denitrificans cytochrome c oxidase have been studied by a combination of second derivative absorption, circular dichroism (cd), and resonance raman spectroscopy. the second derivative absorption and cd spectra reveal changes in the electronic transitions of cytochrome a upon complex formation. these results could reflect changes in ground state heme structure or changes ... | 1992 | 1338946 |
| cytochrome c550 from thiobacillus versutus: cloning, expression in escherichia coli, and purification of the heterologous holoprotein. | the gene coding for cytochrome c550 from thiobacillus versutus, cyca, has been cloned and sequenced. it codes for a protein of 134 amino acids plus a 19-amino-acid-long signal peptide. both coding and noncoding dna sequences of the clone are homologous to the paracoccus denitrificans dna sequence. an expression vector was constructed by cloning the cyca gene directly behind the lac promoter of puc. the cyca gene was expressed in escherichia coli under semianaerobic conditions, and mature holo-cy ... | 1992 | 1339423 |
| structure of holo-chaperonin studied with electron microscopy. oligomeric cpn10 on top of two layers of cpn60 rings with two stripes each. | a structural model of holo-chaperonin, known as a protein-folding control protein comprising 60 kda (cpn60) and 10 kda polypeptides (cpn10), is proposed based on the electron microscopic images of holo-chaperonin from thermus thermophilus and cpn60 from paracoccus denitrificans. isolated paracoccus cpn60 shows very similar images to those of escherichia coli tetradecameric cpn60, a seven-membered ring in the top view and a rectangular shape with four stripes in the side view. however, a small nu ... | 1992 | 1347504 |
| purification and some properties of glutamate dehydrogenase and glutamine synthetase from paracoccus denitrificans. | the purification and some properties of nadp-dependent glutamate dehydrogenase (gdh) and glutamine synthetase (gs) from the facultatively anaerobic gram-negative bacterium paracoccus denitrificans were investigated. the enzymes were purified to homogeneity using a procedure which involved affinity chromatography on blue sepharose cl-6b as the major purification step. the recoveries in the purification of gdh and gs were 28% and 64%, respectively. the specific activity of purified gdh was 183 nka ... | 1992 | 1356141 |
| three-dimensional structure of the quinoprotein methylamine dehydrogenase from paracoccus denitrificans determined by molecular replacement at 2.8 a resolution. | the three-dimensional structure of the quinoprotein methylamine dehydrogenase from paracoccus dentrificans (pd-madh) has been determined at 2.8 a resolution by the molecular replacement method combined with map averaging procedures, using data collected from an area detector. the structure of methylamine dehydrogenase from thio-bacillus versutus, which contains an "x-ray" sequence, was used as the starting search model. madh consists of 2 heavy (h) and 2 light (l) subunits related by a molecular ... | 1992 | 1409575 |
| genes for a second terminal oxidase in bradyrhizobium japonicum. | bradyrhizobium japonicum possesses a mitochondria-like respiratory chain terminating with an aa3-type cytochrome c oxidase. the gene for subunit i of this enzyme (coxa) had been identified and cloned previously via heterologous hybridization using a paracoccus denitrificans dna probe. in the course of these studies, another b. japonicum dna region was discovered which apparently encoded a second terminal oxidase that was different from cytochrome aa3 but also belonged to the superfamily of heme/ ... | 1992 | 1444719 |
| an fnr-dependent promoter from escherichia coli is active and anaerobically inducible in paracoccus denitrificans. | a transcriptional fusion of a synthetic fnr-dependent promoter derived from escherichia coli has been introduced into paracoccus denitrificans on a broad-host-range plasmid. the patterns of expression of beta-galactosidase from this fusion and from a control which is not regulated by fnr have been studied. the results indicate that p. denitrificans expresses a transcriptional regulator which has a very similar dna-binding specificity to fnr, and responds to a similar physiological signal. | 1992 | 1459402 |
| coordinate expression of the enzymes of nitric oxide metabolism in paracoccus denitrificans. | cellular activities of nitric oxide producing nitrite reductase (nir) and nitric oxide reductase (nor) in paracoccus denitrificans increased in parallel upon anaerobic adaptation of aerobically grown cells. in addition, both activities exhibited comparable dependences on oxygen supply into the growing culture. the results suggest that the maintenance of a sufficiently high nor/nir activity ratio plays an important role in preventing nitric oxide accumulation and its toxic effects on the cells du ... | 1992 | 1482406 |
| reactions of benzylamines with methylamine dehydrogenase. evidence for a carbanionic reaction intermediate and reaction mechanism similar to eukaryotic quinoproteins. | it had been previously reported that aromatic amines were not substrates for the bacterial quinoprotein methylamine dehydrogenase. in this study, benzylamine-dependent activity was also not observed in the steady-state assay of this enzyme with the artificial electron acceptor phenazine ethosulfate (pes). benzylamines did, however, stoichiometrically reduce the protein-bound tryptophan tryptophylquinone (ttq) prosthetic group and acted as reversible competitive inhibitors of methylamine oxidatio ... | 1992 | 1554720 |
| oxidation of dithiothreitol during turnover of nitric oxide reductase: evidence for generation of nitroxyl with the enzyme from paracoccus denitrificans. | the stoichiometric relationship between thiol oxidized and no reduced was studied for the reaction catalyzed by nitric oxide reductase from paracoccus denitrificans. the reaction systems consisted of dithiothreitol, ascorbate, phenazine methosulfate, enzyme and no, or that system minus ascorbate. the mole ratio of thiol groups oxidized to no reduced was observed to be 2.3 to 1.5 over a range of no from 0.09 to 0.35 mumol. a ratio of 1.0 was expected for the simple reduction of no by 1-electron t ... | 1992 | 1567412 |
| metabolic pathways in paracoccus denitrificans and closely related bacteria in relation to the phylogeny of prokaryotes. | denitrification and methylotrophy in paracoccus denitrificans are discussed. the properties of the enzymes of denitrification: the nitrate-nitrite antiporter, nitrate reductase, nitrite reductase, nitric oxide reductase and nitrous oxide reductase are described. the genes for none of these proteins have yet been cloned and sequenced from p. denitrificans. a number of sequences are available for enzymes from escherichia coli, pseudomonas stutzeri and pseudomonas aeruginosa. it is concluded that p ... | 1992 | 1575465 |
| structural and redox relationships between paracoccus denitrificans, porcine and human electron-transferring flavoproteins. | electron-transferring flavoprotein (etf) was purified from the bacterium paracoccus denitrificans and the structural and redox relationships to the porcine and human etfs were investigated. the three proteins have essentially identical subunit masses and the alpha-helix content of the bacterial and porcine etfs are very similar, indicating global structural similarity. an anti-(porcine etf) polyclonal antibody that crossreacts with the human large and small subunits also crossreacts strongly wit ... | 1992 | 1576992 |
| the genetic organization of the mau gene cluster of the facultative autotroph paracoccus denitrificans. | the mau gene cluster from paracoccus denitrificans was cloned. the regions of a cloned fragment carrying genes for the small and the large subunit of the methylamine dehydrogenase were identified and sequenced. open reading frames for the madh small subunit gene and the madh large subunit gene were identified. three other open reading frames coding polypeptides with unknown function were found in the sequence. the small subunit gene sequence data reveal that the madh small subunit polypeptide fr ... | 1992 | 1590782 |
| crystal structure of an electron-transfer complex between methylamine dehydrogenase and amicyanin. | the crystal structure of the complex between the quinoprotein methylamine dehydrogenase (madh) and the type i blue copper protein amicyanin, both from paracoccus denitrificans, has been determined at 2.5-a resolution using molecular replacement. the search model was madh from thiobacillus versutus. the amicyanin could be located in an averaged electron density difference map and the model improved by refinement and model building procedures. nine beta-strands are observed within the amicyanin mo ... | 1992 | 1599920 |
| cofactor-directed inactivation by nucleophilic amines of the quinoprotein methylamine dehydrogenase from paracoccus denitrificans. | phenylhydrazine, semicarbazide, aminoguanidine, hydrazine, and hydroxylamine each irreversibly inactivated methylamine dehydrogenase from paracoccus denitrificans and caused changes in the absorbance spectrum of the protein-bound tryptophan tryptophylquinone [ttq] prosthetic group. different spectral perturbations were observed on reaction with each of these inactivators. in each case a stoichiometry of 2 mol per mol of enzyme (1:1 per cofactor) was required to observe complete modification of t ... | 1992 | 1599932 |
| structural features of the 66-kda subunit of the energy-transducing nadh-ubiquinone oxidoreductase (ndh-1) of paracoccus denitrificans. | the structural gene of the paracoccus denitrificans nadh-ubiquinone oxidoreductase encoding a homologue of the 75-kda subunit of bovine complex i (nqo3) has been located and sequenced. it is located approximately 1 kbp downstream of the gene coding for the nadh-binding subunit (nqo1) [xu, x., matsuno-yagi, a., and yagi, t. (1991) biochemistry 30, 6422-6428] and is composed of 2019 base pairs and codes for 673 amino acid residues with a calculated molecular weight of 73,159. the m(r) 66,000 polyp ... | 1992 | 1605643 |
| the energy-transducing nadh-quinone oxidoreductase (ndh-1) of paracoccus denitrificans. | | 1992 | 1633184 |
| gene cluster of the energy-transducing nadh-quinone oxidoreductase of paracoccus denitrificans: characterization of four structural gene products. | in previous reports from our laboratory, the three structural genes (nqo1, nqo2, and nqo3) of the energy-transducing nadh-quinone oxidoreductase of paracoccus denitrificans were characterized [xu, x., matsuno-yagi, a., & yagi, t. (1991) biochemistry 30, 6422-6428; (1991) biochemistry 30, 8678-8684; (1992) arch. biochem. biophys. 296, 40-48]. in this report, the four structural genes nqo4, nqo5, nqo6, and nqo7 of the same paracoccus denitrificans oxidoreductase were cloned and sequenced. on the b ... | 1992 | 1637825 |
| nitric oxide reductase. purification from paracoccus denitrificans with use of a single column and some characteristics. | nitric oxide reductase was purified from paracoccus denitrificans very nearly to homogeneity by a simple method that involved the use of octyl glucoside to solubilize the enzyme from membranes and required a single hydroxyapatite column. the enzyme had specific activities of about 10 mumol no reduced x min-1 x mg-1 at ph 6.5 in an amperometric assay system using phenazine methosulfate/ascorbate as the reducing agent and about 22 mumol no reduced x min-1 x mg-1 at ph 5.0, which is the optimum ph. ... | 1991 | 1645715 |
| the functions and synthesis of bacterial c-type cytochromes with particular reference to paracoccus denitrificans and rhodobacter capsulatus. | | 1991 | 1646010 |
| the cytochrome c peroxidase of paracoccus denitrificans. | the size, visible absorption spectra, nature of haem and haem content suggest that the cytochrome c peroxidase of paracoccus denitrificans is related to that of pseudomonas aeruginosa. however, the paracoccus enzyme shows a preference for cytochrome c donors with a positively charged 'front surface' and in this respect resembles the cytochrome c peroxidase from saccharomyces cerevisiae. paracoccus cytochrome c-550 is the best electron donor tested and, in spite of an acidic isoelectric point, ha ... | 1991 | 1646012 |
| evidence for the role of soluble cytochrome c in the dissimilatory reduction of nitrite and nitrous oxide by cells of paracoccus denitrificans. | the role of periplasmic cytochrome c in the denitrification pathway has been investigated using a wild-type and/or a cytochrome c deficient strain of paracoccus denitrificans. the reconstitution experiments with the isolated proteins showed that bacterial cytochrome c-550 restored the electron transport from the cytoplasmic membrane to soluble nitrite reductase (cytochrome cd1). in response to decreased aeration lasting 3 h, the huug25 strain synthesized nitrous-oxide reductase significantly sta ... | 1991 | 1646632 |
| the cytochrome c reductase/oxidase respiratory pathway of paracoccus denitrificans: genetic and functional studies. | data are presented on three components of the quinol oxidation branch of the paracoccus respiratory chain: cytochrome c reductase, cytochrome c552, and the a-type terminal oxidase. deletion mutants in the bc1 and the aa3 complex give insight into electron pathways, assembly processes, and stability of both redox complexes, and, moreover, are an important prerequisite for future site-directed mutagenesis experiments. in addition, evidence for a role of cytochrome c552 in electron transport betwee ... | 1991 | 1646794 |
| the three-subunit cytochrome bc1 complex of paracoccus denitrificans. its physiological function, structure, and mechanism of electron transfer and energy transduction. | the cytochrome bc1 complex purified from p. denitrificans has the same electron-transfer and energy-transducing activities, is sensitive to the same electron-transfer inhibitors, and contains cytochromes b, c1, iron-sulfur protein, and thermodynamically stable ubisemiquinone identical to the counterpart complexes from mitochondria. however, the bacterial bc1 complex consists of only three proteins, the obligate electron-transfer proteins, while the mitochondrial complexes contain six or more sup ... | 1991 | 1646795 |
| genes coding for cytochrome c oxidase in paracoccus denitrificans. | several loci on the paracoccus denitrificans chromosome are involved in the synthesis of cytochrome c oxidase. so far three genetic loci have been isolated. one of them contains the structural genes of subunits ii and iii, as well as two regulatory genes which probably code for oxidase-specific assembly factors. in addition, two distinct genes for subunit i have been cloned, one of which is located adjacent to the cytochrome c550 gene. an alignment of six promoter regions reveals only short comm ... | 1991 | 1646796 |
| cytochrome c oxidase in paracoccus denitrificans. protein, chemical, structural, and evolutionary aspects. | preparations and protein chemical characterizations performed with cytochrome c oxidase (e.c. 1.9.3.1) from the purple bacterium paracoccus denitrificans are reviewed. the simplest catalytically competent complex of the enzyme consists of two subunits of 62012 and 2799 da. the theoretical heme a/protein ratio of the purified enzyme is 22.0 nmol/mg. the amino acid sequences of both proteins are compared with examples of subunits i and ii of mitochondrial terminal oxidases from the main kingdoms o ... | 1991 | 1646797 |
| cytochrome c oxidase metal centers: location and function. | cytochrome c oxidase of paracoccus denitrificans is spectroscopically and functionally very similar to the mammalian enzyme. however, it has a very much simpler quaternary structure, consisting of only three subunits instead of the 13 of the bovine enzyme. the known primary structure of the paracoccus denitrificans subunits, the knowledge of a large number of sequences from other species, and data on the controlled proteolytic digestion of the enzyme allow structural restrictions to be placed on ... | 1991 | 1646798 |
| the reactions of the oxidase and reductases of paracoccus denitrificans with cytochromes c. | electron transport in the paracoccus denitrificans respiratory chain system is considerably more rapid when it includes the membrane-bound cytochrome c552 than with either soluble paracoccus c550 or bovine cytochrome c; a pool function for cytochrome c is not necessary. low concentrations of paracoccus or bovine cytochrome c stimulate the oxidase activity. this observation could explain the multiphasic scatchard plots which are obtained. a negatively charged area on the "back side" of paracoccus ... | 1991 | 1646799 |
| evolutionary aspects of cytochrome c oxidase. | the presence of additional subunits in cytochrome oxidase distinguish the multicellular eukaryotic enzyme from that of a simple unicellular bacterial enzyme. the number of these additional subunits increases with increasing evolutionary stage of the organism. subunits i-iii of the eukaryotic enzyme are related to the three bacterial subunits, and they are encoded on mitochondrial dna. the additional subunits are nuclear encoded. experimental evidences are presented here to indicate that the lowe ... | 1991 | 1646800 |
| the gene encoding cytochrome c oxidase subunit ii from rhodobacter sphaeroides; comparison of the deduced amino acid sequence with sequences of corresponding peptides from other species. | the gene (coxii) encoding subunit ii of rhodobacter sphaeroides cytochrome c oxidase (cytochrome aa3) has been isolated by screening a genomic dna library in phage lambda with a probe derived from coxii of paracoccus denitrificans. a 2-kb fragment containing coxii dna was subcloned into the phage m13mp18 and the sequence determined. the 2-kb insert contains the entire coding region for coxii gene, including the atg start codon and a tga stop codon. the deduced amino acid (aa) sequence of subunit ... | 1991 | 1648008 |
| subunit iii of cytochrome c oxidase is not involved in proton translocation: a site-directed mutagenesis study. | subunit iii (coiii) is one of the three core subunits of the aa3-type cytochrome c oxidase. coiii does not contain any of the redox centres and can be removed from the purified enzyme but has a function during biosynthesis of the enzyme. dicyclohexyl carbodiimide (dccd) modifies a conserved glutamic acid residue in coiii and abolishes the proton translocation activity of the enzyme. in this study, the invariant carboxylic acids e98 (the dccd-binding glutamic acid) and d259 of coiii were changed ... | 1991 | 1648477 |
| cytochrome c2 is essential for electron transfer to nitrous oxide reductase from physiological substrates in rhodobacter capsulatus and can act as an electron donor to the reductase in vitro. correlation with photoinhibition studies. | 1. addition of nitrous oxide to a periplasmic fraction released from rhodobacter capsulatus strains mt1131, n22dnar+ or ad2 caused oxidation of c-type cytochrome, as judged by the decrease in absorbance at 550 nm. the periplasmic fraction catalysed reduction of nitrous oxide in the presence of either isoascorbate plus phenazine ethosulphate or reduced methyl viologen. the rates with these two electron donors were similar and were comparable to the activity observed with a quantity of cells equiv ... | 1991 | 1651241 |
| cytochrome c' of paracoccus denitrificans. | cytochrome c' was identified in periplasmic extracts of the paracoccus denitrificans strains lmd 22.21 and lmd 52.44. the cytochrome c' was purified from the latter using the device of sequential molecular exclusion chromatography in the dimeric and monomeric states. although showing the overall spectroscopic features of the cytochrome c' family, the paracoccus cytochrome c' is unusual in having a red-shifted oxidised soret band at 407 nm. also unusual is the midpoint potential of 202 mv, well a ... | 1991 | 1653018 |
| potentiometric and spectral studies with the two-subunit cytochrome aa3 from paracoccus denitrificans. comparison with the 13-subunit beef heart enzyme. | previous work from this laboratory has revealed a complex and interactive redox behavior for the active metal centers in beef heart cytochrome aa3. all of these centers are contained in two of the 13 subunits which make up the enzyme. the isolated cytochrome aa3 of paracoccus denitrificans contains only two subunits. the purpose of the current investigation was to see if the complex redox behavior is dependent on the presence of the additional 11 peptides that are present in the mammalian enzyme ... | 1991 | 1655082 |
| comparison of energy-transducing capabilities of the two- and three-subunit cytochromes aa3 from paracoccus denitrificans and the 13-subunit beef heart enzyme. | in the accompanying paper, we have shown that the two-subunit cytochrome aa3 isolated from paracoccus denitrificans displays the same kind of complex and interactive redox behavior as the 13-subunit cytochrome aa3 from beef heart. therefore, the redox characteristics are not dependent on the additional 11 subunits. in the current work, we have examined the energy-transducing capabilities of both the two- and three-subunit enzymes obtained from paracoccus denitrificans in relation to that of the ... | 1991 | 1655083 |
| 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 ... | 1991 | 1657871 |
| a method for introduction of unmarked mutations in the genome of paracoccus denitrificans: construction of strains with multiple mutations in the genes encoding periplasmic cytochromes c550, c551i, and c553i. | a new suicide vector, prvs1, was constructed to facilitate the site-directed introduction of unmarked mutations in the chromosome of paracoccus denitrificans. the vector was derived from suicide vector pgrpd1, which was equipped with the lacz gene encoding beta-galactosidase. the reporter gene was found to be a successful screening marker for the discrimination between plasmid integrant strains and mutant strains which had lost the plasmid after homologous recombination. suicide vectors pgrpd1 a ... | 1991 | 1657872 |
| 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 ... | 1991 | 1657873 |
| molecular cloning of the cytochrome aa3 gene from the archaeon (archaebacterium) halobacterium halobium. | a novel aa3-type cytochrome oxidase from the extremely halophilic archaeon, halobacterium halobium, differs significantly from those of other prokaryotic and eukaryotic cytochrome oxidases (fujiwara, t., fukumori, y., and yamanaka, t. (1989) j. biochem. 105, 287-292). in the present study, we cloned and sequenced the gene which encodes the cytochrome aa3 by using the polymerase chain reaction methods. the deduced amino acid sequence of subunit i of h. halobium cytochrome aa3 was more similar to ... | 1991 | 1659810 |
| 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 |
| removal of nitrate from water by cells of paracoccus denitrificans in a membrane flow reactor. | a new type of flow bioreactor designed to remove nitrate from water was developed. denitrification activity of native paracoccus denitrificans cells was used, the cells being separated from the refined medium by a semipermeable membrane. relationships between the degree of nitrate conversion and the denitrification rate, on the one hand, and the volume flow rate and the amount of biomass, on the other, together with the results concerning denitrification during closed-circuit recirculation of th ... | 1991 | 1668747 |
| assimilation of ammonia in paracoccus denitrificans. | two pathways serve for assimilation of ammonia in paracoccus denitrificans. glutamate dehydrogenase (nadp+) catalyzes the assimilation at a high nh4+ concentration. if nitrate serves as the nitrogen source, glutamate is synthesized by glutamate-ammonia ligase and glutamate synthase (nadph). at a very low nh4+ concentration, all three enzymes are synthesized simultaneously. no direct relationship exists between glutamate dehydrogenase (nadp+) and glutamate-ammonia ligase in p. denitrificans, whil ... | 1991 | 1688163 |
| the production and utilization of nitric oxide by a new, denitrifying strain of pseudomonas aeruginosa. | when a new strain of pseudomonas aeruginosa was grown aerobically and then transferred to anaerobic conditions, cells reduced no3- quantitatively to no2- in no3(-)-respiration. in the absence of nitrate, no2- was immediately reduced to no or n2o but not to n2 indicating that no2(-)-reductase but not n2o-reductase was active. the formation of the products no or n2o depended on the ph in the medium and the concentration of no2- present. when p. aeruginosa was grown anaerobically for at least three ... | 1991 | 1772347 |
| using the bacterium, paracoccus denitrificans and other 'runaway mitochondria' as classroom models for respiratory electron transport studies. | our suggestions for experiments demonstrating electron-transport-chain composition and reactions all exploit bacteria which can be prepared quickly, easily and cheaply from cells grown in erlenmeyer flasks. while they have been designed from a cytochrome oxidase point of view using organisms of our own prejudice, strains containing mutations in other sites could be just as educational. most bacteria that can grow aerobically have features in common with the mitochondrial respiratory chain. becau ... | 1991 | 1794596 |
| determination of nitrate by conversion to nitrite using paracoccus denitrificans. | a new method of determination of nitrate was developed, utilizing the nitrate reductase activity of paracoccus denitrificans in which a further reduction of nitrate is blocked either by a mutation affecting formation of cytochromes c or by inhibition of the electron flow to nitrite reductase by mucidin. after deproteinization of the sample with zinc acetate the nitrite produced is determined colorimetrically. | 1991 | 1823647 |
| the f0 subunits of bovine mitochondrial atp synthase complex: purification, antibody production, and interspecies cross-immunoreactivity. | the known subunits of the membrane sector f0 of the bovine mitochondrial atp synthase complex are subunits b, d, 6, f6, oscp (oligomycin sensitivity-conferring protein), the dccd (dicyclohexylcarbodiimide) binding proteolipid, and a6l. the first six subunits were purified from smp or preparations of the atp synthase complex, and monospecific antibodies were raised against each. the antisera were shown to be competent for immuno-blotting, and each antiserum recognized a single polypeptide of the ... | 1991 | 1824914 |
| increase in spermine content coordinated with siderophore production in paracoccus denitrificans. | spermine is present in relatively low amounts in paracoccus denitrificans cultured aerobically in an ammonium succinate minimal salts medium supplemented with 50 microm iron(iii). however, in iron-deprived cultures [minimal salts medium containing 0.5 microm iron(iii)], spermine content increases by an order of magnitude in coordination with the well-known responses to iron derivation, e.g., derepression of siderophore synthesis and siderophore excretion. when iron-deprived cultures exhibiting b ... | 1991 | 1826103 |
| the bacillus subtilis cytochrome-c oxidase. variations on a conserved protein theme. | the structural genes of cytochrome-c oxidase in bacillus subtilis have been isolated and sequenced. five genes, ctab-f, are closely spaced. ctac, ctad, ctae and ctaf are the genes for subunits ii, i, iii and ivb, respectively, ctab, which may encode an assembly factor, is separated and upstream from the others. in comparison to its mitochondrial counterparts, subunit i has an extended c-terminus with two additional transmembrane segments, whereas subunit iii has lost two such segments from its n ... | 1991 | 1847686 |
| paracoccus denitrificans mutants deleted in the gene for subunit ii of cytochrome c oxidase also lack subunit i. | as a prerequisite to site-directed mutagenesis on cytochrome c oxidase, two different mutants are constructed by inactivating the cta gene locus encoding subunits ii and iii (ctac and ctae) of the paracoccus denitrificans oxidase. either a short fragment encoding part of the putative copper binding site near the c terminus of subunit ii, or a substantial fragment, comprising parts of the coding region for both subunits and all of the intervening three open reading frames, are removed and replace ... | 1991 | 1850416 |
| resolution of the electronic transitions of cytochrome c oxidase: evidence for two conformational states of ferrous cytochrome alpha. | second-derivative absorption spectra are reported for a variety of oxidation and ligation states of bovine cytochrome c oxidase (ferrocytochrome-c:oxygen oxidoreductase, ec 1.9.3.1). the high resolving power of the second-derivative method allows us to assign the individual electronic transitions of cytochrome alpha and cytochrome alpha 3 in many of these states. in the fully reduced enzyme, one observes a single electronic transition at 444 nm, corresponding to the soret transition for both fer ... | 1991 | 1852001 |
| crystallographic investigations of the tryptophan-derived cofactor in the quinoprotein methylamine dehydrogenase. | a model of tryptophan tryptophylquinone (ttq), recently proposed by mcintire et al. (science (1991) 252, 817-824) to be the prosthetic group of the quinoprotein methylamine dehydrogenase, has been compared with electron density maps of this dehydrogenase from thiobacillus versutus and paracoccus denitrificans. the comparison shows that the ttq model can be neatly accommodated, providing strong supportive evidence that ttq is indeed the cofactor for this group of quinoproteins. | 1991 | 1879526 |
| characterization of the tryptophan-derived quinone cofactor of methylamine dehydrogenase by resonance raman spectroscopy. | the resonance raman (rr) spectrum of oxidized methylamine dehydrogenase (madhox) exhibits a set of c-h, c-c, c = c, and c = o vibrational modes between 900 and 1700 cm-1 that are characteristic of the quinone moiety of the tryptophan tryptophlyquinone (ttq) cofactor. the close similarity of the rr spectra for madhs from paracoccus denitrificans (pd), thiobacillus versutus (tv), and bacterium w3a1 proves that the same cofactor is present in all three proteins. the madhs from pd and tv have a v(c ... | 1991 | 1892829 |
| identification of the nadh-binding subunit of energy-transducing nadh-quinone oxidoreductase (ndh-1) of thermus thermophilus hb-8. | the energy-transducing nadh--quinone oxidoreductase (ndh-1) isolated from thermus thermophilus hb-8 is composed of approximately 10 unlike polypeptides and contains noncovalently bound fmn and at least three iron-sulfur clusters [yagi, t., hon-nami, k., and ohnishi, t. (1988) biochemistry 27, 2008-2013]. when ndh-1 of t. thermophilus hb-8 was irradiated by short uv light in the presence of [adenylate-32p]nadh or [adenylate-32p]nad, radioactivity was incorporated into a single polypeptide of mr 4 ... | 1991 | 1899572 |
| inhibitory effects of two structurally related carbocyanine laser dyes on the activity of bovine heart mitochondrial and paracoccus denitrificans nadh-ubiquinone reductase. evidence for a rotenone-type mechanism. | two cationic, lipophilic laser dyes, 1,1',3,3,3',3'-hexamethylindodicarbocyanine iodide (hidc) and 1,1',3,3,3',3'-hexamethylindotricarbocyanine iodide (hitc), inhibit bovine heart mitochondrial and paracoccus denitrificans nadh oxidase activities. the mitochondrial i50 values were 0.5 microm (hidc) and 1.2 microm (hitc), and the p. denitrificans i50 values 1.2 microm (hidc) and 1.5 microm (hitc). neither succinate nor cytochrome oxidase (ec 1.9.3.1) activities were inhibited significantly by eit ... | 1991 | 1900156 |
| anaerobic degradation of cresols by denitrifying bacteria. | the initial reactions in anaerobic metabolism of methylphenols (cresols) and dimethylphenols were studied with denitrifying bacteria. a newly isolated strain, possibly a paracoccus sp., was able to grow on o- or p-cresol as sole organic substrate with a generation time of 11 h; o- or p-cresol was completely oxidized to co2 with nitrate being reduced to n2. a denitrifying pseudomonas-like strain oxidized m- or -p-cresol as the sole organic growth substrate completely to co2 with a generation time ... | 1991 | 1904702 |
| the nadh-binding subunit of the energy-transducing nadh-ubiquinone oxidoreductase of paracoccus denitrificans: gene cloning and deduced primary structure. | the nadh dehydrogenase complex isolated from paracoccus denitrificans is composed of approximately 10 unlike polypeptides and contains noncovalently bound fmn, non-heme iron, and acid-labile sulfide [yagi, t. (1986) arch. biochem. biophys. 250, 302-311]. the nadh-binding subunit (mr = 50,000) of this enzyme complex was identified by direct photoaffinity labeling with [32p]nadh [yagi, t., & dinh, t.m. (1990) biochemistry 29, 5515-5520]. primers were synthesized on the basis of the n-terminal amin ... | 1991 | 1905152 |
| characterization of the 25-kilodalton subunit of the energy-transducing nadh-ubiquinone oxidoreductase of paracoccus denitrificans: sequence similarity to the 24-kilodalton subunit of the flavoprotein fraction of mammalian complex i. | the nadh dehydrogenase complex isolated from paracoccus denitrificans is composed of approximately 10 unlike polypeptides [yagi, t. (1986) arch. biochem. biophys. 250, 302-311]. structural genes encoding the subunits of this enzyme complex constitute at least one gene cluster [xu, x., matsuno-yagi, a., & yagi, t. (1991) biochemistry 30, 6422-6428]. the 25-kda subunit (nqo2), which has been isolated from sodium dodecyl sulfate-polyacrylamide gels, is a polypeptide of this enzyme complex. the part ... | 1991 | 1909571 |
| identification of the dna region responsible for sulfur-oxidizing ability of thiosphaera pantotropha. | for the identification of the dna region responsible for the sulfur-oxidizing ability (sox) of thiosphaera pantotropha, we used previously isolated tn5-mob insertional sox- mutants. for seven mutants, the tn5-mob insertion was localized on the chromosome rather than on the megaplasmids phg41 or phg42 by using the tn5-mob-harboring vehicle psup5011 as probe. the specific insertion of tn5-mob into a sox gene was determined for one sox- mutant, strain tp19. an 18-kb ecori fragment was cloned in esc ... | 1991 | 1938925 |
| rapid purification of cytochrome c oxidase from paracoccus denitrificans. | two methods are described for the purification of cytochrome c oxidase from triton x-100 extracts of the periplasma membrane of paracoccus denitrificans. the first is a large-scale procedure for the preparation of 100-250 nmol of cytochrome c oxidase (10-20 mg) in 1 week. the second is a rapid procedure for isolating up to 25 nmol in 2-3 days. owing to the high yields given by fast protein liquid chromatography (fplc) on mono q columns, the overall yield is about 20%, whereas the yield in many o ... | 1990 | 1962788 |
| review article: structural and functional properties of cytochrome aa3 from bacteria. | the aa3 oxidases from bacteria form a group of related enzymes that resemble the far more complex mitochondrial cytochrome c oxidase, both functionally and structurally. these enzymes catalyze electron transfer from ferrocytochrome c to oxygen to produce water. this transfer is coupled to proton translocation. several oxidases of this type have been purified from cytoplasmic membranes of bacteria. this review summarizes the present knowledge on purified bacterial aa3 oxidases and correlates thes ... | 1990 | 1963305 |
| nucleotide sequence of the gene coding for four subunits of cytochrome c oxidase from the thermophilic bacterium ps3. | the gene coding for four subunits of cytochrome aa3-type oxidase was isolated from a genomic dna library of the thermophilic bacterium ps3 and sequenced. the n-terminus of each subunit was also sequenced to verify the initiation site of the reading frame. the deduced amino acid sequences contained 615 amino acid residues for subunit i (co1/caab product), 333 residues for subunit ii (co2/caaa product), 207 residues for subunit iii (co3/caac product), and 109 residues for subunit iv (co4/caad prod ... | 1990 | 1964459 |
| inhibition by cyclopropylamine of the quinoprotein methylamine dehydrogenase is mechanism-based and causes covalent cross-linking of alpha and beta subunits. | cyclopropylamine acted as a mechanism-based inhibitor of the quinoprotein methylamine dehydrogenase from paracoccus denitrificans. the protein-bound quinone cofactor of this enzyme was rapidly reduced by addition of a stoichiometric amount of cyclopropylamine, but this compound did not serve as a substrate for the enzyme in the steady-state kinetic assay. time-dependent inactivation of the enzyme by cyclopropylamine was observed only in the presence of a reoxidant. saturation behavior was observ ... | 1991 | 1993204 |
| paracoccus denitrificans. | | 1991 | 2050652 |
| metabolic regulation including anaerobic metabolism in paracoccus denitrificans. | under anaerobic circumstances in the presence of nitrate paracoccus denitrificans is able to denitrify. the properties of the reductases involved in nitrate reductase, nitrite reductase, nitric oxide reductase, and nitrous oxide reductase are described. for that purpose not only the properties of the enzymes of p. denitrificans are considered but also those from escherichia coli, pseudomonas aeruginosa, and pseudomonas stutzeri. nitrate reductase consists of three subunits: the alpha subunit con ... | 1991 | 2050653 |
| c1 metabolism in paracoccus denitrificans: genetics of paracoccus denitrificans. | paracoccus denitrificans is able to grow on the c1 compounds methanol and methylamine. these compounds are oxidized to formaldehyde which is subsequently oxidized via formate to carbon dioxide. biomass is produced by carbon dioxide fixation via the ribulose biphosphate pathway. the first oxidation reaction is catalyzed by the enzymes methanol dehydrogenase and methylamine dehydrogenase, respectively. both enzymes contain two different subunits in an alpha 2 beta 2 configuration. the genes encodi ... | 1991 | 2050654 |
| bacterial nadh-quinone oxidoreductases. | the nadh-quinone oxidoreductases of the bacterial respiratory chain could be divided in two groups depending on whether they bear an energy-coupling site. those enzymes that bear the coupling site are designated as nadh dehydrogenase 1 (ndh-1) and those that do not as nadh dehydrogenase 2 (ndh-2). all members of the ndh-1 group analyzed to date are multiple polypeptide enzymes and contain noncovalently bound fmn and iron-sulfur clusters as prosthetic groups. the nadh-ubiquinone-1 reductase activ ... | 1991 | 2050655 |
| molecular cloning of the l-phenylalanine transaminase gene from paracoccus denitrificans in escherichia coli k-12. | the l-phenylalanine transaminase gene of paracoccus denitrificans was cloned by a shotgun method using the escherichia coli k-12 mutant dg30, which lacks three distinct transaminase genes. plasmid ppap142 was constructed by inserting a 2.2-kb fragment carrying the transaminase gene into puc18. strain e. coli k-12 hb101 cells harboring the plasmid produced 20-fold to 30-fold more transaminase than wild type p. denitrificans cells. the nucleotide sequence of the 2.2-kb fragment was determined, rev ... | 1991 | 2054101 |
| 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 ... | 1990 | 2116368 |
| identification of the nadh-binding subunit of nadh-ubiquinone oxidoreductase of paracoccus denitrificans. | the nadh dehydrogenase complex isolated from paracoccus denitrificans is composed of approximately 10 unlike polypeptides and contains noncovalently bound fmn, non-heme iron, and acid-labile sulfide [yagi, t. (1986) arch. biochem. biophys. 250, 302-311]. when the paracoccus nadh dehydrogenase complex was irradiated by uv light in the presence of [adenylate-32p]nad, radioactivity was incorporated exclusively into one of three polypeptides of mr approximately 50,000. similar results were obtained ... | 1990 | 2117469 |
| radiorespirometry evidence for the discrimination between 13c-enriched glucose and unlabelled glucose molecules by paracoccus denitrificans. | paracoccus denitrificans was grown on either unlabelled glucose, [1-13c]glucose or [6-13c]glucose as the sole carbon source for growth. the cells were then incubated with a range of 14c-glucose substrates to compare the 14co2-evolution rates between cells grown on the glucose and the 13c-labelled glucose. cells grown on 13c-glucose had significantly faster rates of 14co2-evolution than those grown on unlabelled glucose. the % yields of 14co2, per [1-14c]-, [6-14c]- and [u-14c]glucose supplied we ... | 1990 | 2117553 |
| inhibition by capsaicin of nadh-quinone oxidoreductases is correlated with the presence of energy-coupling site 1 in various organisms. | the nadh-ubiquinone reductase activity of the respiratory chains of several organisms was inhibited by capsaicin and dihydrocapsaicin, which are the pungent principles of red pepper. this inhibition was correlated with the presence of an energy transducing site in this segment of the respiratory chain. where the nadh-quinone oxidoreductase segment involved an energy coupling site (e.g., in paracoccus denitrificans, escherichia coli, and thermus thermophilus hb-8 membranes and bovine heart mitoch ... | 1990 | 2118334 |
| genetics of carbon metabolism in methylotrophic bacteria. | the application of genetic techniques to the methylotrophic bacteria has greatly enhanced studies of these important organisms. two methylotrophic systems have been studied in some detail, the serine cycle for formaldehyde assimilation and the methanol oxidation system. in both cases, genes have been cloned and mapped in methylobacterium species (facultative serine cycle methanol-utilizers). in addition, methanol oxidation genes have been studied in an autotrophic methanol-utilizer (paracoccus d ... | 1990 | 2128803 |
| kinetics of oxidative phosphorylation in paracoccus denitrificans. 1. mechanism of atp synthesis at the active site(s) of f0f1-atpase. | (1) the rate of atp synthesis during nadh-driven aerobic respiration has been measured in plasma membrane vesicles from paracoccus denitrificans as a function of the concentration of the substrates, adp and inorganic phosphate (pi). in both cases, the response of the reaction to changes in the degree of saturation of the f0f1-atpase generated a perfect micaelian dependence which allowed the determination of the corresponding michaelis constants, kmadp and kmpi. (2) these kinetic parameters posse ... | 1990 | 2148690 |
| kinetics of oxidative phosphorylation in paracoccus denitrificans. 2. evidence for a kinetic and thermodynamic modulation of f0f1-atpase by the activity of the respiratory chain. | (1) the affinity of the f0f1-atpase from paracoccus denitrificans for atp during nadh-driven oxidative phosphorylation has been analyzed under different conditions by examining the type and extent of product inhibition. (2) a limited collapse of the protonmotive force (delta p) due to partial uncoupling does not increase the affinity for atp at the active site(s) of the enzyme; instead, a partial noncompetitive inhibition becomes apparent, compatible with the binding of atp to a noncatalytic sit ... | 1990 | 2148691 |
| mutagenesis of the gene encoding cytochrome c550 of paracoccus denitrificans and analysis of the resultant physiological effects. | by using synthetic oligonucleotides, the gene encoding soluble cytochrome c550 was isolated from a genomic bank of paracoccus denitrificans. the nucleotide sequence of the gene was determined, and the deduced amino acid sequence of the mature protein was found to be similar to the primary structure of purified cytochrome c550 except for the presence of seven additional amino acid residues at the c terminus. at the n terminus of the primary structure was found an additional stretch of 19 amino ac ... | 1990 | 2153663 |
| are there isoenzymes of cytochrome c oxidase in paracoccus denitrificans? | we have used a gene replacement strategy to delete the previously isolated gene [(1987) embo j. 6, 2825-2833] for the cytochrome c oxidase subunit i from paracoccus denitrificans. the resulting mutant was still able to synthesize active cytochrome c oxidase. this led us to look for another locus which could completely suppress the mutation. in this study we report the isolation of a second gene encoding subunit i. an open reading frame coding for cytochrome c 550 was found upstream from this gen ... | 1990 | 2155830 |
| paracoccus denitrificans cytochrome c1 gene replacement mutants. | we describe the construction and characterization of gene replacement mutants for the respiratory chain component cytochrome c1 in the bacterium paracoccus denitrificans. its structural gene (fbcc) was inactivated by insertion of the kanamycin resistance gene, introduced into a suicide vector, and conjugated into paracoccus; chromosomal mutants obtained by homologous recombination were selected by antibiotic resistance screening and further characterized biochemically. they showed the complete s ... | 1990 | 2158969 |
| mutagenesis of the gene encoding cytochrome c550 of paracoccus denitrificans and analysis of the resultant physiological effects. | | 1990 | 2160949 |
| nitric oxide formed by nitrite reductase of paracoccus denitrificans is sufficiently stable to inhibit cytochrome oxidase activity and is reduced by its reductase under aerobic conditions. | nitric oxide, generated by the action of purified nitrite reductase, inhibited the oxidase activity of both membrane vesicles from anaerobically grown paracoccus denitrificans and bovine heart submitochondrial particles. in the former case, the inhibition was relatively short-lived and its duration was reduced either by decreasing the concentration of nitrite or raising the ratio of vesicles to nitrite reductase enzyme. these observations indicate that nitric oxide, at least at low concentration ... | 1990 | 2161257 |
| complete amino acid sequence of the cytochrome subunit and amino-terminal sequence of the flavin subunit of flavocytochrome c (sulfide dehydrogenase) from chlorobium thiosulfatophilum. | the complete amino acid sequence of the 86-residue heme subunit of flavocytochrome c (sulfide dehydrogenase) from the green phototrophic bacterium chlorobium thiosulfatophilum strain tassajara has been determined as follows: apeqsksiprgeilslscagchgtdgksesiiptiygrsaeyiesalldfksga- rpstvmgrhakgysdeeihqiaeyfgslstmnn. the subunit has a single heme-binding site near the n terminus, consisting of a pair of cysteine residues at positions 18 and 21. the out-of-plane ligands are apparently contributed by ... | 1990 | 2161842 |
| the sequence of the cyo operon indicates substantial structural similarities between the cytochrome o ubiquinol oxidase of escherichia coli and the aa3-type family of cytochrome c oxidases. | the cytochrome o complex is one of two ubiquinol oxidases in the aerobic respiratory system of escherichia coli. this enzyme catalyzes the two-electron oxidation of ubiquinol-8 which is located in the cytoplasmic membrane, and the four-electron reduction of molecular oxygen to water. the purified oxidase contains at least four subunits by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and has been shown to couple electron flux to the generation of a proton motive force across ... | 1990 | 2162835 |
| the nitric oxide reductase of paracoccus denitrificans. | the nitric oxide (no) reductase activity of the cytoplasmic membrane of paracoccus denitrificans can be solubilized in dodecyl maltoside with good retention of activity. the solubilized enzyme lacks nadh-dependent activity, but can be assayed with isoascorbate plus 2,3,5,6-tetramethylphenylene-1,4-diamine as electron donor and with horse heart cytochrome c as mediator. reduction of no was measured with an amperomeric electrode. the solubilized enzyme could be separated from other electron-transp ... | 1990 | 2167070 |
| cox10 codes for a protein homologous to the orf1 product of paracoccus denitrificans and is required for the synthesis of yeast cytochrome oxidase. | respiratory-defective mutants of saccharomyces cerevisiae assigned to pet complementation group g19 lack cytochrome oxidase activity and cytochromes a and a3. the enzyme deficiency is caused by recessive mutations in the nuclear gene cox10. analyses of cytochrome oxidase subunits suggest that the product of cox10 provides an essential function at a posttranslational stage of enzyme assembly. the wild type cox10 gene has been cloned by transformation of a mutant from complementation group g19 wit ... | 1990 | 2167310 |
| cytochrome oxidase assembly in yeast requires the product of cox11, a homolog of the p. denitrificans protein encoded by orf3. | the synthesis of cytochrome oxidase in saccharomyces cerevisiae was recently shown to require a protein encoded by the nuclear gene cox10. this protein was found to be homologous to the putative protein product of the open reading frame orf1 reported in one of the cytochrome oxidase operons of paracoccus denitrificans. in the present study we demonstrate the existence in yeast of a second nuclear gene, cox11, whose encoded protein is homologous to another open reading frame (orf3) present in the ... | 1990 | 2167832 |
| apo forms of cytochrome c550 and cytochrome cd1 are translocated to the periplasm of paracoccus denitrificans in the absence of haem incorporation caused either mutation or inhibition of haem synthesis. | an apo form of cytochrome c550 can be detected by immunoblotting cell-free extracts of a mutant of paracoccus denitrificans that is deficient in c-type cytochromes. this apoprotein is found predominantly in the periplasm, the location of the holocytochrome in the wild-type organism, indicating that translocation of the polypeptide occurs in the absence of haem attachment. the polypeptide molecular weight, as judged by sodium dodecyl sulphate/polyacrylamide gel electrophoresis, is indistinguishab ... | 1990 | 2172694 |
| the cellular location and specificity of bacterial cytochrome c peroxidases. | the locations of cytochrome c peroxidase and catalase activities in the two gram-negative bacteria pseudomonas stutzeri (n.c.i.b. 9721) and paracoccus denitrificans (n.c.i.b. 8944) were investigated by the production of spheroplasts. in both species the cytochrome c peroxidase was predominantly periplasmic: 92% of total activity in ps. stutzeri and 98% of nonmembrane-bound activity in pa. denitrificans were found in this cellular compartment. in contrast, the catalase was mostly in the cytoplasm ... | 1990 | 2173903 |
| kinetics of iron acquisition from ferric siderophores by paracoccus denitrificans. | the kinetics of iron accumulation by iron-starved paracoccus denitrificans during the first 2 min of exposure to 55fe-labeled ferric siderophore chelates is described. iron is acquired from the ferric chelate of the natural siderophore l-parabactin in a process exhibiting biphastic kinetics by lineweaver-burk analysis. the kinetic data for 1 microm less than [fe l-parabactin] less than 10 microm fit a regression line which suggests a low-affinity system (km = 3.9 +/- 1.2 microm, vmax = 494 pg-at ... | 1990 | 2185228 |
| mutagenesis of the gene encoding amicyanin of paracoccus denitrificans and the resultant effect on methylamine oxidation. | the gene encoding the blue-copper protein amicyanin was isolated from a genomic bank of paracoccus denitrificans by using a synthetic oligonucleotide. it is located directly downstream of the gene encoding the small subunit of methylamine dehydrogenase. amicyanin is transcribed as a precursor protein with a signal sequence, typical for periplasmic proteins. specific inactivation of amicyanin by means of gene replacement techniques resulted in the complete loss of the ability to grow on methylami ... | 1990 | 2261991 |
| formation of a potent respiratory inhibitor at nitrite reduction by nitrite reductase isolated from the bacterium paracoccus denitrificans. | a new method of dissimilatory nitrite reductase (cytochrome cd1) isolation from the periplasmic fraction of anaerobically grown cells of the bacterium paracoccus denitrificans was developed, using ionex and gel permeation chromatography with fplc system (pharmacia, sweden). in experiments with isolated enzyme it was shown that through a nitrite reduction, catalysed by this enzyme, a substance (presumably nitric oxide) was formed which at submicromolar concentrations inhibited terminal cytochrome ... | 1990 | 2266492 |
| hydroxylamine as an inhibitor and terminal acceptor in the respiratory chain of the bacterium paracoccus denitrificans. | three sites of inhibitory action of hydroxylamine were identified in the respiratory chain of anaerobically grown bacterium paracoccus denitrificans. terminal oxidases were blocked at concentrations of 10(-4) to 10(-3) mol.l-1, and the inhibitor competed with artificial donor of electrons n, n, n', n'-tetramethyl-l, 4-phenylenediamine. in the anaerobic part of the respiratory chain inhibition of nitrite reductase and apparently also nitric oxide reductase occurred, resulting in the increased acc ... | 1990 | 2269422 |
| ph-dependent semiquinone formation by methylamine dehydrogenase from paracoccus denitrificans. evidence for intermolecular electron transfer between quinone cofactors. | the quinonoid confactors of paracoccus denitrificans methylamine dehydrogenase exhibited a ph-dependent redistribution of electrons from the 50% reduced plus 50% oxidized to the 100% semiquinone redox form. this phenomenon was only observed at ph values greater than 7.5. the semiquinone was not readily reduced by addition of methylamine, consistent with the view that this substrate donates two electrons at a time to each cofactor during catalysis. once formed at ph 9.0, no change in redox state ... | 1990 | 2271681 |
| the kinetic and isotopic competence of nitric oxide as an intermediate in denitrification. | rates of no uptake by five denitrifying bacteria were estimated by no-electrode and gas chromatography methods under conditions of rather low cell densities and [noaq]. the rates so measured, vmaxno, represent lower limits for the true value of that parameter, but nevertheless exceed vmax for nitrite uptake, vmaxni, by a factor of two typically. previous estimates under suboptimal conditions had placed vmaxno at 0.3-0.5 of vmaxni (st. john, r. t., and hollocher, t. c. (1977) j. biol. chem. 252, ... | 1990 | 2295624 |