Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nucleotide sequence of the pet operon of Rhodopseudomonas capsulata strain SB1003 has been determined. This operon consists of the petA, petB and petC genes, which encode the Rieske Fe-S protein, cytochrome b and cytochrome c1, respectively, all components of the ubiquinol-cytochrome c2 oxidoreductase. The deduced amino acid sequences of the pet genes show homology to the corresponding proteins from other organisms, and particularly high homologies (over 90% for amino acid and nucleotide sequences) to the previously described fbc operon from a strain previously identified as Rhodopseudomonas spheroides GA. The amino acid sequences of the pet proteins are discussed with reference to the structure and function of the ubiquinol-cytochrome c2 oxidoreductase.
J Mol Biol 1987 May 05
PMID:Primary structure of the bc1 complex of Rhodopseudomonas capsulata. Nucleotide sequence of the pet operon encoding the Rieske cytochrome b, and cytochrome c1 apoproteins. 282 Dec 68

Detailed comparison of the 'Rhodopseudomonas sphaeroides GA' strain used by Gabellini et al. (1985) with genuine R. sphaeroides and R. capsulata strains indicated that the previously reported fbc operon of R. sphaeroides (Gabellini and Sebald, 1986) encoding the structural genes for the Rieske Fe-S protein, cytochrome b and cytochrome c1 subunits of the ubiquinol:cytochrome c2 oxidoreductase, is not from R. sphaeroides, but is rather from a strain of R. capsulata. Consequently, the genuine bc1 genes from R. sphaeroides were cloned using corresponding R. capsulata genes as probes, and a partial nucleotide sequence for the Rieske Fe-S protein of R. sphaeroides was determined and compared with that of R. capsulata.
J Mol Biol 1987 May 05
PMID:fbc operon, encoding the Rieske Fe-S protein cytochrome b, and cytochrome c1 apoproteins previously described from Rhodopseudomonas sphaeroides, is from Rhodopseudomonas capsulata. 282 Dec 72

A series of mouse lines with increased resistance to respiratory inhibitors which block electron transport through the protonmotive cytochrome b of complex III have been isolated in this laboratory. We describe here the isolation of a mutant with increased resistance to HQNO (2-n-heptyl-4-hydroxyquinoline-N-oxide) whose phenotype is due to a nuclear mutation. At the cellular level, there is a severe reduction in respiration with the residual oxygen consumption being resistant to inhibitors of both ubiquinol-cytochrome c oxidoreductase and cytochrome oxidase. At the mitochondrial level, there was a severe derangement in NADH oxidase activity. Electron transport through the succinate oxidase span of the respiratory chain and its coupling to oxidative phosphorylation are also reduced in this nuclear mutant but not to the same extent. It is concluded that the primary defect in the mutant lies within a nuclear gene encoding a component of complex I (NADH-ubiquinol oxidoreductase). In addition, further biochemical characterization of the mitochondrially inherited inhibitor-resistant mutants has demonstrated that they also show significant reductions in the efficiency of energy transduction and in the rate of cytochrome b electron transport.
Somat Cell Mol Genet 1987 Sep
PMID:Characterization of mouse nuclear and mitochondrial mutants with increased resistance to cytochrome b inhibitors. 282 32

The single nuclear gene encoding the 11-kDa subunit VIII of the ubiquinol-cytochrome-c oxidoreductase (complex III) in Saccharomyces cerevisiae has been inactivated by a one-step gene disruption procedure. Inactivation results in a loss of ubiquinol-cytochrome-c oxidoreductase activity (less than 1% wild type) and respiratory deficiency. Cells lacking the 11-kDa protein also display lowered steady-state levels of other complex-III subunits encoded by nuclear genes including the 14-kDa subunit VII and the Rieske Fe-S protein and of the mitochondrially encoded cytochrome b. The steady-state levels of the transcripts from the genes encoding these proteins are however not reduced. The results strongly imply that the 11-kDa protein plays an important role in regulating the synthesis of complex III at the post-transcriptional level, most likely assembly. Separation of chromosomes by pulsed-field gel electrophoresis of DNA of wild-type and of the mutant lacking the 11-kDa-protein gene followed by Southern blot analysis reveals that the latter gene is located on chromosome X rather than on XII as reported by Van Loon et al. [Mol. Gen. Genet. 197 (1984) 219-224].
 ...
PMID:Inactivation of the gene encoding the 11-kDa subunit VIII of the ubiquinol-cytochrome-c oxidoreductase in Saccharomyces cerevisiae. 283 Oct 58

Highly purified preparations of plasma membranes from control and ketoconazole-treated (1 microM, 120 h) epimastigotes of Trypanosoma cruzi have been obtained by cell disruption using abrasion with glass beads, differential centrifugation and isopycnic centrifugation in continuous, self-generating Percoll gradients. The purity of the preparation was ascertained by the specific activity 125I bound to the membranes obtained from enzymatically radiolabeled epimastigotes and by the alpha-methyl-mannoside sensitive binding of 125I-concanavalin A. The membranes form closed vesicles of 0.2-0.4 micron in diameter which display Mg2+ ATPase and acid phosphatase activities, but are devoid of 5'-nucleotidase and succinate-cytochrome c oxidoreductase; these vesicles can be strongly agglutinated by concanavalin A. The lipid order profiles of membranes from control and treated cells were compared with that present in egg phosphatidylcholine/ergosterol liposomes (84:16, mol/mol) by electron spin resonance spectroscopy of doxylstearic acid probes with the nitroxide group bound to carbon 5, 10, 12 and 16 of the stearic acid chain. Membranes from treated epimastigotes have a lipid order profile which resembles that of control plasma membranes near the polar surface (positions 5 and 10) but there is an abrupt decrease of order at position 12 and from there to the center of bilayer is highly disordered, even more than in pure lipid membranes. Consistent with these results, the leakage of L-[14C]glucose from membrane vesicles of ketoconazole-treated cells is much faster than that observed in vesicles obtained from control cells. These results indicate a strong alteration of the plasma membrane physical and biological properties due to the incubation of the parasite with the drug; this alteration is consistent with the accumulation of methylated precursors of ergosterol, which affects both lipid-lipid and lipid-protein interactions in the membrane.
Mol Biochem Parasitol 1988 Aug
PMID:Alteration of lipid order profile and permeability of plasma membranes from Trypanosoma cruzi epimastigotes grown in the presence of ketoconazole. 284 68

The pit+ gene, encoding the phosphate (inorganic) transport system of Escherichia coli, was isolated from a library of E. coli genes inserted in the cosmid vector pHC79. A 25.5-kb chromosomal DNA fragment was shown also to carry the gor locus encoding glutathione oxidoreductase. Physical mapping placed the two genes about 10 kb apart, confirming bacteriophage P1 mapping of the 77-min region. Subcloning and deletion analysis indicated that the entire pit+ gene was located within a 2.2-kb Sal1-Ava1 fragment. The pit+ gene product was identified by SDS-polyacrylamide gel electrophoresis as a 39-kdal inner membrane protein by two methods: 35S-methionine-labelling of minicells carrying pit+ plasmids or plasmids from which all or part of the pit+ gene was deleted. Overproduction of the Pit protein using a thermoinducible "runaway" replication plasmid. Complementation of the pit-1 mutant allele using a unit-copy-number pit+ plasmid indicated that the pit-1 mutation is recessive. Strains carrying a multicopy pit+ plasmid show a 10-fold increase in the initial rate of phosphate uptake; however there is no change in the steady-state level of 32Pi accumulation.
Mol Gen Genet 1986 Sep
PMID:Molecular cloning of the phosphate (inorganic) transport (pit) gene of Escherichia coli K12. Identification of the pit+ gene product and physical mapping of the pit-gor region of the chromosome. 302 Mar 81

The complete nucleotide sequence (24,206 base-pairs) of the Klebsiella pneumoniae gene region for nitrogen fixation (nif) is presented. Coding regions corresponding to the 19 known nif genes (including nifW and nifZ) could be identified. An additional open reading frame of 216 base-pairs, called nifT, was detected between nifK and nifY. Search for transcriptional signal structures revealed some unusual features: (1) several possible NifA-binding motifs are present in the intergenic regions between nifJ and nifH as well as between nifX and nifU; (2) a perfect NifA-binding motif, preceding the nifENX promoter, is located within an inverted repeat structure; (3) structures resembling the consensus nif promoter are found within the coding regions of nifW and nifZ and, together with a NifA-binding motif, in nifN. Typical rho-independent termination structures were detected only downstream from the nifHDKTY and the nifBQ operons. Analysis of the deduced amino acid sequences revealed the presence of two Cys-X2-Cys-X2-Cys-X3-Cys-Pro clusters in the pyruvate-flavodoxin oxidoreductase NifJ. This arrangement of cysteine residues is normally present only in ferredoxins. A high degree of homology between the two gene products (NifE and NifN) involved in iron-molybdenum cofactor biosynthesis and the two nitrogenase component I structural proteins (NifD and NifK) was found. All four proteins are characterized by the conserved motif His-Gly-X2-Gly-Cys, which may play a role in binding the iron-molybdenum cofactor.
J Mol Biol 1988 Oct 05
PMID:Nucleotide sequence of a 24,206-base-pair DNA fragment carrying the entire nitrogen fixation gene cluster of Klebsiella pneumoniae. 306 78

Hydrogenosomes isolated from Tritrichomonas foetus and Trichomonas vaginalis fermented pyruvate to acetate, malate, H2, and CO2 in an anaerobic process dependent on ADP, Pi, Mg2+, and succinate. The extent to which pyruvate was carboxylated to malate by malate dehydrogenase (decarboxylating) rather than decarboxylated to acetate by pyruvate/ferredoxin oxidoreductase was dependent on pCO2. The processes observed showed carbon and redox balances. The presence of an NADH/ferredoxin oxidoreductase activity was demonstrated. This enzyme is likely to be involved in the transfer of electrons from the ferredoxin reduced in pyruvate oxidation to NAD+ needed for the reductive carboxylation of pyruvate. Disruption of hydrogenosomes with Triton X-100 led to cessation of pyruvate-dependent H2 formation which could be restored by addition of coenzyme A and methyl viologen or ferredoxin. The formation of acetate and H2 by undisrupted hydrogenosomes proceeded at approximately half maximal rates in the presence of 25 microM succinate for T. foetus and 5 microM succinate for T. vaginalis. The apparent Km value of the acetate/succinate CoA transferase from T. foetus for succinate was approximately 45 microM, thus the stimulating effect of succinate might be due to the requirement of this enzyme for succinate. The exact mechanism of this effect remains to be elucidated, however.
Mol Biochem Parasitol 1986 Jul
PMID:Anaerobic pyruvate metabolism of Tritrichomonas foetus and Trichomonas vaginalis hydrogenosomes. 309 Apr 35

It was shown that the blockage of epsilon-amino group of Lis-126 residue by 2,2,6,6-tetramethyl-4-oxo-piperidine-1-oxyl (TMPO) leads to the cooperative inactivation of glutamate dehydrogenase (L-glutamate-NAD(P)-oxidoreductase, EC 1.4.1.3). The data concerning cooperative inactivation of the enzyme are interpreted by the model of hexamer with identical orientation of subunits. It was shown that the modification of any of enzyme subunits is accompanied by an inactivation of the hexamer's fragment which is a dimer, with subunits interacting reciprocally by means of isological contacts.
Mol Biol (Mosk)
PMID:[Cooperative inactivation of glutamate dehydrogenase of 2,2,6,6- tetramethyl-4-oxopiperidine-1-oxyl. Interpretation of results within the scope of a hexamer model with equivalent subunit orientation]. 325 50

In Escherichia coli the six known genes specifying the utilization of L-fucose as carbon and energy source cluster at 60.2 min and constitute a regulon. These genes include fucP (encoding L-fucose permease), fucI (encoding L-fucose isomerase), fucK (encoding L-fuculose kinase), fucA (encoding L-fuculose 1-phosphate aldolase), fucO (encoding L-1,2-propanediol oxidoreductase), and fucR (encoding the regulatory protein). In this study the fuc genes were cloned and their positions on the chromosome were established by restriction endonuclease and complementation analyses. Clockwise, the gene order is: fucO-fucA-fucP-fucI-fucK-fucR. The operons comprising the structural genes and the direction of transcription were determined by complementation analysis and Southern blot hybridization. The fucPIK and fucA operons are transcribed clockwise. The fucO operon is transcribed counterclockwise. The fucR gene product activates the three structural operons in trans.
Mol Gen Genet 1987 Dec
PMID:The organization of the fuc regulon specifying L-fucose dissimilation in Escherichia coli K12 as determined by gene cloning. 332 79


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>