J Gen Microbiol
December 1986
A transcript analysis of the citrate synthase and succinate dehydrogenase genes (gltA-sdhCDAB) of Escherichia coli was done by nuclease S1 mapping. Evidence was obtained for two monocistronic gltA transcripts extending anti-clockwise, to a common terminus, from independent promoters with start points 196 bp (major) and 299 bp (minor) upstream of the gltA coding region. Evidence was also obtained for two polycistronic sdh transcripts, sdhCDAB (minor) and sdhDAB (major), extending clockwise, from sites 219 bp upstream of sdhC and 1455 bp upstream of sdhD (i.
View Article and Find Full Text PDFJ Steroid Biochem
October 1986
Uterine enzymes involved in the intermediary metabolism of glucose have been measured in the androgenized rat in which there is evidence of diminution of the oestrogenic responses despite raised glycogen and glucose typical of maximal oestrogenic stimulation. Phosphofructokinase and isocitrate dehydrogenase (NADP, cytosolic) activities were significantly decreased in the androgenized rat and were elevated following treatment with natural progesterone and synthetic progestins which partially reverse the uterine abnormalities of the androgenized rat. Mitochondrial protein was decreased in the uterus of the androgenized rat but there was an apparent sparing effect on isocitrate (NAD) and malate (NAD) dehydrogenase.
View Article and Find Full Text PDFThe aroP gene of Escherichia coli K-12 was located in a ca. 1.2-kilobase region of DNA.
View Article and Find Full Text PDFThe nucleotide sequences of two segments of DNA (2250 and 2921 base-pairs) containing the functionally related fumarase (fumC) and aspartase (aspA) genes of Escherichia coli K12 were determined. The fumC structural gene comprises 1398 base-pairs (466 codons, excluding the initiation codon), and it encodes a polypeptide of Mr 50353 that resembles the fumarases of Bacillus subtilis 168 (citG-gene product), rat liver and pig heart. The fumC gene starts 140 base-pairs downstream of the structurally-unrelated fumA gene, but there is no evidence that both genes form part of the same operon.
View Article and Find Full Text PDFLambda phages containing the aconitase gene (acn) of Escherichia coli K12 have been isolated by hybridization with an M13 probe containing part of the aconitase gene (citB) of Bacillus subtilis. Aconitase specific activities are amplified 5- to 18-fold in thermally induced lambda acn lysogens and threefold in a strain transformed with a plasmid derivative (pGS181).
View Article and Find Full Text PDFJ Gen Microbiol
June 1986
The genes encoding both subunits of the succinyl-CoA synthetase of Escherichia coli have been identified as distal genes of the suc operon, which also encodes the dehydrogenase (Elo; sucA) and succinyltransferase (E2o; sucB) components of the 2-oxoglutarate dehydrogenase complex. The newly defined genes express polypeptides of 41 kDa (sucC) and 31 kDa (sucD), corresponding to the beta and alpha subunits of succinyl-CoA synthetase, respectively. The genes are thus located at 16.
View Article and Find Full Text PDFThe nucleotide sequence was determined for the first part of the Bacillus subtilis sdh operon. An open reading frame corresponding to the structural gene, sdhA, for cytochrome b558 was identified. The predicted molecular weight of the cytochrome (excluding the N-terminal methionine) is 22,770.
View Article and Find Full Text PDFWe have investigated the presence, duration, and clinical significance of granulocyte accumulation, using indium-111 granulocyte scanning, in patients following uncomplicated intestinal anastomosis. Eight patients underwent intestinal resection and anastomosis (right hemicolectomy, 5; sigmoid colectomy, 2; ileal resection, 1) for carcinoma, angiodysplasia, or perforation. All patients had an uneventful postoperative course, with no evidence of any leakage or infection.
View Article and Find Full Text PDFThe fumB gene of Escherichia coli, which complements the fumarase deficiency of a fumA mutant when present in multiple copies, has been located at 93.5 min in the E. coli linkage map and its product has been identified as a polypeptide of 61 kDal.
View Article and Find Full Text PDFThe primary structure of the succinyl-CoA synthetase of Escherichia coli has been deduced from the nucleotide sequence of a 2451-base-pair segment of DNA containing the corresponding sucC (beta subunit) and sucD (alpha subunit) genes. The genes are located at one end of a gene cluster that encodes several citric acid cycle enzymes: gltA-sdhCDAB-sucABCD; gltA, citrate synthase; sdh, succinate dehydrogenase; sucA and sucB, the dehydrogenase (E1) and succinyltransferase (E2) components of the 2-oxoglutarate dehydrogenase complex. The sucC and sucD genes are separated from the sucA and sucB genes by a 273-base-pair segment containing four palindromic units, but they appear to be expressed from a sucABCD read-through transcript that extends from the suc promoter to a potential rho-independent terminator at the distal end of sucD.
View Article and Find Full Text PDFThe dihydrolipoamide acetyltransferase component (E2p) of the pyruvate dehydrogenase complex of Escherichia coli contains three highly homologous sequences of about 100 residues that are tandemly repeated to form the N-terminal half of the polypeptide chain. All three sequences include a lysine residue that is a site for lipoylation and they appear to form independently folded functional domains. These lipoyl domains are in turn linked to a much larger (about 300 residues) subunit-binding domain of the E2p chain that aggregates to form the octahedral inner core of the complex and also contains the acetyltransferase active site.
View Article and Find Full Text PDFNucleic Acids Res
January 1985
The nucleotide sequence of a 2.14 kb fragment of Bacillus subtilis DNA containing the citG gene encoding fumarase was determined using the dideoxy chain termination method. The citG coding region of 1392 base pairs (464 codons) was identified, and the deduced Mr (50425) is in good agreement with that of the protein identified from expression in Escherichia coli maxicells.
View Article and Find Full Text PDFThe Fnr protein, the transcriptional regulator of the expression of anaerobic respiratory functions in Escherichia coli, was purified to homogeneity from soluble extracts of a strain harbouring the fnr gene in an expression vector. The identity of the isolated protein was confirmed by comparing its amino-terminal sequence with that predicted from nucleotide sequence of the fnr gene. It appeared that eight amino-terminal amino acids had been removed post-translationally from the bulk of the isolated Fnr protein.
View Article and Find Full Text PDFMol Gen Genet
October 1985
Transcript mapping of the Escherichia coli sucAB, aceEF and lpd genes, encoding the five components of the pyruvate and 2-oxoglutarate dehydrogenase complexes, was carried out using single-stranded M13 probes. The sucA and aceE genes encode the specific dehydrogenase components (E1o, E1p), and the sucB and aceF genes encode the specific dihydrolipoamide acyltransferases (E2o, E2p). The common lipoamide dehydrogenase (E3) component is encoded by a single lpd gene adjacent to the aceEF genes.
View Article and Find Full Text PDFA 1.6-kb MspI-HindIII chromosomal DNA segment, carrying the complete coding region of the 6-phosphomannose isomerase (PMI) structural gene, manA, and the 5' end of the gene encoding the major fumarase activity, fumA, of Escherichia coli K-12, has been sequenced using the chain termination method. The start points of manA and fumA transcripts were located by S1 mapping using 32P-labelled M13 ssDNA probes, and the two genes were shown to be transcribed divergently.
View Article and Find Full Text PDFThe fumarase (citG) gene of Bacillus subtilis 168 has been identified in a collection of lambda phages carrying EcoRI-generated fragments of B. subtilis DNA. Regions of the cloned DNA have been subcloned into plasmid vectors, and the ability of prophages and multicopy plasmids to complement Escherichia coli and B.
View Article and Find Full Text PDFThe nucleotide sequence of a 961 base-pair segment of DNA containing the sdhB gene, which encodes the iron-sulphur protein subunit of the E. coli succinate dehydrogenase, has been determined. The sdhB structural gene comprises 711 base pairs (237 codons, excluding the translational initiator and terminator).
View Article and Find Full Text PDFThe nucleotide sequence of a 3614 base-pair segment of DNA containing the sdhA gene, encoding the flavoprotein subunit of succinate dehydrogenase of Escherichia coli, and two genes sdhC and sdhD, encoding small hydrophobic subunits, has been determined. Together with the iron-sulphur protein gene (sdhB) these genes form an operon (sdhCDAB) situated between the citrate synthase gene (gltA) and the 2-oxoglutarate dehydrogenase complex genes (sucAB): gltA-sdhCDAB-sucAB. Transcription of the gltA and sdhCDAB gene appears to diverge from a single intergenic region that contains two pairs of potential promoter sequences and two putative CRP (cyclic AMP receptor protein)-binding sites.
View Article and Find Full Text PDFThe nucleotide sequence of the sucB gene, which encodes the dihydrolipoamide succinyltransferase component (E2o) of the 2-oxoglutarate dehydrogenase complex of Escherichia coli K12, has been determined by the dideoxy chain-termination method. The results extend by 1440 base pairs the previously reported sequence of 3180 base pairs, containing the sucA gene. The sucB structural gene comprises 1209 base pairs (403 codons excluding the initiating AUG), and it is preceded by a 14-base-pair intercistronic region containing a good ribosomal binding site.
View Article and Find Full Text PDFThe nucleotide sequence of a 3180-base-pair segment of DNA, containing the sucA gene encoding the 2-oxoglutarate dehydrogenase component (E1o) of the 2-oxoglutarate dehydrogenase complex of Escherichia coli, has been determined by the dideoxy chain-termination method. The sucA structural gene contains 2796 base pairs (932 codons, excluding the initiation codon AUG) and encodes a polypeptide having a glutamine residue at the amino terminus, a glutamate residue at the carboxy-terminus and a calculated Mr = 104905. The predicted amino acid composition is in good agreement with published information obtained by hydrolysis of the purified enzyme.
View Article and Find Full Text PDFThe expression of the fumarate reductase system of Escherichia coli is completely dependent on the presence of adenylate cyclase or cyclic AMP, but the cyclic AMP receptor protein (CRP) is not required. This suggests that cyclic AMP may function as an effector for a second gene activator protein, possibly Fnr, and thus form part of a redox-sensitive regulatory mechanism controlling the expression of anaerobic respiratory functions.
View Article and Find Full Text PDFThe aspartase gene (aspA) of Escherichia coli has been isolated in two plasmids, pGS73 and pGS94, which contain segments of bacterial DNA (12.5 and 2.8 kb, respectively) inserted into the tet gene of the vector pBR322.
View Article and Find Full Text PDFNucleic Acids Res
April 1984
The nucleotide sequence of a 2.41 kb fragment of E. coli DNA containing the fumA gene encoding fumarase was determined using the dideoxy chain termination method.
View Article and Find Full Text PDFThe elucidation of the primary structure of the Escherichia coli lipoamide dehydrogenase (EC 1.8.1.
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