Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of expression plasmids containing either the complete insert from plasmid pUCDBK1 (Peoples et al., 1987) or sub-fragments thereof were constructed in a tac promoter vector. Analysis of protein lysates of induced cultures of these clones identified the gene encoding NADPH-specific acetoacetyl-CoA reductase in the 2.3kb of sequence located downstream from the beta-ketothiolase gene in plasmid pUCDBK1. The complete nucleotide sequence (2.1kb) of this region was determined. An open reading frame was located 88bp downstream from the stop codon of the thiolase gene encoding a potential polypeptide of Mr 25,000, which is in good agreement with that observed for the overexpressed protein on SDS-PAGE. N-terminal protein sequence data obtained by Edman degradation of the purified Mr = 25,000 polypeptide were used to identify the correct start of the NADPH-specific acetoacetyl-CoA reductase gene. Hence in Z. ramigera, the genes encoding beta-ketothiolase (phbA) and NADPH-specific acetoacetyl-CoA reductase (phbB) are organized as phbA-phbB. S1-nuclease analysis of Z. ramigera RNA identified a transcription start site 85 bp upstream from the phbA structural gene locating the promoter region.
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PMID:Fine structural analysis of the Zoogloea ramigera phbA-phbB locus encoding beta-ketothiolase and acetoacetyl-CoA reductase: nucleotide sequence of phbB. 254 4

A membrane-bound cytochrome b, a heterodimer formed by a 91-kD glycoprotein and a 22-kD polypeptide, is a critical component of the phagocyte NADPH-oxidase responsible for the generation of superoxide anion. Mutations in the gene for the 91-kD chain of this cytochrome result in the X-linked form of chronic granulomatous disease (CGD), in which phagocytes are unable to produce superoxide. Typically, there is a marked deficiency of the 91-kD subunit and the cytochrome spectrum is absent (X- CGD). In a variant form of CGD with X-linked inheritance, affected males have a normal visible absorbance spectrum of cytochrome b, yet fail to generate superoxide (X+ CGD). The size and abundance of the mRNA for the 91-kD subunit and its encoded protein were examined and appeared normal. To search for a putative mutation in the coding sequence of the 91-kD subunit gene, the corresponding RNA from an affected X+ male was amplified by the polymerase chain reaction and sequenced. A single nucleotide change, a C----A transversion, was identified that predicts a nonconservative Pro----His substitution at residue 415 of the encoded protein. Hybridization of amplified genomic DNA with allele-specific oligonucleotide probes demonstrated the mutation to be specific to affected X+ males and the carrier state. These results strengthen the concept that all X-linked CGD relates to mutations affecting the expression or structure of the 91-kD cytochrome b subunit. The mechanism by which the Pro 415----His mutation renders the oxidase nonfunctional is unknown, but may involve an impaired interaction with other components of the oxidase.
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PMID:A missense mutation in the neutrophil cytochrome b heavy chain in cytochrome-positive X-linked chronic granulomatous disease. 255 53

The X-ray structure analyses of four glutathione reductase complexes and derivatives have been extended to 2 A resolution and refined. The results are discussed in conjunction with the structure of the oxidized native enzyme known at 1.54 A resolution. While the residual co-ordinate errors are around 0.2 A, some significant shifts even in this range could be established. Points of particular interest are the 3.2 A approach of C4N of nicotinamide to N5F of flavin in hydride transfer geometry, the hydrogen bond geometries of the 2'-phosphate of NADPH as compared to inferior geometries for an inorganic phosphate binding together with NADH, the differential mobilities of parts of the substrates as derived from refined atomic temperature factors, and the stabilization of the thiolate of the proximal Cys63 by conformational changes of neighboring residues as well as by flavin. In addition, catalytically competent His467' is seen to interact more optimally with the sulfur of glutathione-I than with the distal sulfur of Cys58. The observed participation of water molecules for both NADPH and glutathione binding is so extensive that a prediction of the binding mode merely from the polypeptide structure would be very difficult. The accurately known geometries allowed us to draw some conclusions on the enzyme mechanism and suggest a possible scenario of the catalysis.
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PMID:Substrate binding and catalysis by glutathione reductase as derived from refined enzyme: substrate crystal structures at 2 A resolution. 258 16

The gene encoding barbiturate-inducible cytochrome P-450BM-1 from Bacillus megaterium ATCC 14581 has been cloned and sequenced. An open reading frame in the 1.9 kb of cloned DNA correctly predicted the NH2-terminal sequence of P-450BM-1 previously determined by protein sequencing, and, in toto, predicted a polypeptide of 410 amino acid residues with an Mr of 47,439. The sequence is most, but less than 27%, similar to that of P-450CAM from Pseudomonas putida, so that P-450BM-1 clearly belongs to a new P-450-gene family, distinct especially from that of the P-450 domain of P-450BM-3, a barbiturate-inducible single polypeptide cytochrome P-450:NADPH-P-450 reductase from the same strain of B. megaterium (Ruettinger, R.T., Wen, L.-P. and Fulco, A.J. (1989) J. Biol. Chem. 264, 10987-10995).
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PMID:Molecular cloning, coding nucleotides and the deduced amino acid sequence of P-450BM-1 from Bacillus megaterium. 259 81

A gene of the chloroplast genome has been designated the psbG gene on the basis that in maize the gene product is a 24-kDa polypeptide of photosystem two (PS2) (Steinmetz, A. A., Castroviejo, M., Sayre, R. T., and Bogorad, L. (1986) J. Biol. Chem. 261, 2485-2488). We have located and sequenced the equivalent gene in wheat (Triticum aestivum) and have raised specific antibodies to the gene product following its expression in Escherichia coli as a beta-galactosidase fusion protein. Using these antibodies, we have investigated the location of the gene product in various thylakoid membrane fractions of pea (Pisum sativum). The gene product of apparent molecular mass 27-28 kDa is severely depleted in PS2-enriched membrane preparations and its distribution between stromal and granal regions of the membrane is distinct to that of the psbC gene product which is known to be a core polypeptide of PS2. We therefore conclude that psbG does not code for a component of PS2 but instead suggest that it is present in a novel protein complex of the thylakoid membrane. On the basis of 1) the conserved overlap between psbG and ndhC, a chloroplast gene which shows significant homology to a mitochondrial gene that codes for a subunit of the NADH-ubiquinone oxidoreductase of mitochondria, and 2) sequence similarity between the psbG gene product and the ndh gene product of E. coli, which codes for a respiratory NADH dehydrogenase, we propose that this ill-defined complex functions as a NADH or NADPH-plastoquinone oxidoreductase.
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PMID:psbG is not a photosystem two gene but may be an ndh gene. 266 82

The hemoprotein component of Salmonella typhimurium sulfite reductase (NADPH) (EC 1.8.1.2) was purified to homogeneity from cysJ266, a mutant strain lacking sulfite reductase flavoprotein. The siroheme- and Fe4S4-containing enzyme was isolated as a monomeric 63-kDa polypeptide and consisted of a mixture of unligated enzyme and a complex with sulfite. Following reduction with 5'-deazaflavin-EDTA and reoxidation, the complex was converted to the uncomplexed, high spin ferri-siroheme state seen previously with Escherichia coli sulfite reductase hemoprotein preparations. The S. typhimurium hemoprotein exhibited catalytic and physical properties identical to the hemoprotein prepared by urea dissociation of E. coli sulfite reductase holoenzyme and was fully competent in reconstituting NADPH-sulfite reductase activity when combined with excess purified sulfite reductase flavoprotein. The DNA sequences of cysI and cysH from S. typhimurium and E. coli B were determined and, together with previously reported data, confirmed the organization of this region as promoter-cysJ-cysI-cysH with all three genes oriented in the same direction from the promoter. Molecular weights deduced for the cysI-encoded sulfite reductase hemoprotein and for the cysH-encoded 3'-phosphoadenosine 5'-phosphosulfate sulfotransferase were approximately 64,000 and 28,000, respectively. Comparison of the deduced amino acid sequence of sulfite reductase hemoprotein with that of spinach nitrite reductase (Back, E., Burkhart, W., Moyer, M., Privalle, L., and Rothstein, S. (1988) Mol. Gen. Genet. 212, 20-26), which also contains siroheme and an Fe4S4 cluster, showed two groups of cysteine-containing sequences with the structures Cys-(X)3-Cys and Cys-(X)5-Cys, which are homologous in the two enzymes and are postulated to provide the ligands of the Fe4S4 cluster in both proteins. From these sequences and from crystallographic (McRee, D. E., Richardson, D. C., Richardson, J. S., and Siegel, L. M. (1986) J. Biol. Chem. 261, 10277-10281) and spectroscopic data in the literature, a model is proposed for the structure of the active center of these two enzymes.
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PMID:Characterization of the cysJIH regions of Salmonella typhimurium and Escherichia coli B. DNA sequences of cysI and cysH and a model for the siroheme-Fe4S4 active center of sulfite reductase hemoprotein based on amino acid homology with spinach nitrite reductase. 267 Sep 46

The complete amino acid sequence of chicken liver fatty acid synthase [acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl- and enoyl-reducing, and thioester-hydrolyzing), EC 2.3.1.85] has been determined from the corresponding cDNA sequence. A 5.3-kilobase-pair (kbp) region of cDNA coding for chicken fatty acid synthase has been cloned and sequenced that is contiguous to the 2.3-kbp region previously sequenced [Yuan, Z., Liu, W. & Hammes, G.G. (1988) Proc. Natl. Acad. Sci. USA 85, 6328-6331]. The cDNA codes for the remaining 1677 amino acids of the previously unsequenced region of the protein. The amino acid sequence contains peptides known to be associated with the NADPH binding site of the enoylreductase active center, the acetyl/malonyltransacylase active site, the "waiting" site containing cysteine, and a pyridoxal 5'-phosphate binding site. Locations of the NADPH binding site of the beta-ketoacylreductase active site and of the dehydratase active site are proposed on the basis of protein sequence homologies to catalytic sites in other enzymes. The molecular weight of the complete polypeptide chain is 267,288. A linear functional map of the chicken fatty acid synthase derived from its primary sequence is presented.
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PMID:Molecular cloning and sequencing of chicken liver fatty acid synthase cDNA. 273 91

The membrane bound enzyme oxidizing protoporphyrinogen to protoporphyrin, a step in heme and chlorophyll synthesis, was purified to a single prominent polypeptide band on SDS/PAGE from barley mitochondrial fractions. It contained a variety of lipids including 0.66 mg of phosphatidyl ethanolamine and 0.46 mg of free fatty acid per mg of protein. Iron, but no flavins or cytochromes, was detected. In the presence of glutathione, enzymatic oxidation was inhibited by the iron chelator o-phenanthroline but was stimulated by iron EDTA. The purified enzyme was inhibited by reductants such as glutathione, ascorbate, NADH and NADPH. These findings are compatible with some direct or indirect involvement of lipids and iron in this oxidation in plants.
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PMID:Characteristics of purified protoporphyrinogen oxidase from barley. 273 23

Inhibition of bioluminescence in Photobacterium phosphoreum by cerulenin has been demonstrated to be due to a specific inactivation of the acyl-CoA reductase subunit of the fatty acid reductase complex required for synthesis of the aldehyde substrate for the luminescent reaction. In contrast, the activities of the other luminescence-related enzymes, acyl-protein synthetase, acyl-transferase, and luciferase, were unaffected by cerulenin. Myristoyl-CoA, but not NADPH, protected the acyl-CoA reductase against cerulenin inhibition. Cerulenin blocked the acylation of the reductase with myristoyl-CoA and the reaction with N-ethylmaleimide. A shift in mobility of the reductase polypeptide on sodium dodecyl sulfate - polyacrylamide gel electrophoresis occurred after reaction with cerulenin, a shift which could be blocked by reaction with N-ethylmaleimide. These results demonstrate that cerulenin blocks aldehyde synthesis by covalent reaction with the acyl-CoA reductase and indicate that the reaction may occur at a cysteine residue involved in the formation of the acyl-reductase intermediate.
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PMID:Covalent reaction of cerulenin at the active site of acyl-CoA reductase of Photobacterium phosphoreum. 275 74

We have previously reported that addition of Ca2+ and phospholipid (PL) inhibits translation in hemin-containing reticulocyte lysates through activation of a eukaryotic protein synthesis initiation factor (eIF-2) kinase. The possibility that this activation was mediated by a Ca2+-PL-dependent protein kinase (protein kinase C, PKC) appeared unlikely by the observation that it was prevented or reversed by NADPH-generating systems. Nevertheless, reticulocyte lysates contain a potent PKC activity and we deemed it desirable to isolate this enzyme to answer unequivocally the question whether it does or does not activate eIF-2 alpha kinase. We have purified reticulocyte PKC to near homogeneity with Mr 95,500 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme absolutely depended upon both Ca2+ and phosphatidylserine for activity on histone H1 or the beta-subunit of initiation factor eIF-2 and underwent autophosphorylation in a Ca2+- and PL-dependent manner. Mild treatment with trypsin yielded an Mr 82,000 polypeptide that still required Ca2+ and PL for activity. This Mr agrees with that reported for other PKCs, suggesting that these enzymes may undergo limited degradation during isolation. Further proteolytic treatment converted the reticulocyte enzyme into a Ca2+- and PL-dependent form, as is known for PKCs from other sources. The highly purified PKC had no effect on translation in hemin-supplemented reticulocyte lysates.
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PMID:Purification and properties of protein kinase C from rabbit reticulocyte lysates. 282 7


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