Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of acetylornithine delta-transaminase is induced by arginine and by rifampin in an arginine-inducible mutant of Escherichia coli W. A mutant of the arginine-inducible strain was isolated which is resistant to rifampin. The mutation which has brought about rifampin resistance has altered RNA polymerase and has simultaneously altered the regulation of arginine biosynthesis. Three of the enzymes of arginine biosynthesis, acetylornithinase, ornithine transcarbamylase, and argininosuccinase, show a greater rate of derepression and a 2--12-fold higher level of enzyme activity in the rifampin-resistant mutant than in the parent arginine-inducible strain. Acetylornithine delta-transaminase is no longer inducible by rifampin alone, and the level of inducibility by arginine plus rifampin has been reduced by 70%. The results indicate that RNA polymerase is involved in regulation of arginine biosynthesis in E. coli W.
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PMID:Alteration of regulation of arginine biosynthesis in Escherichia coli W by mutation to rifampin resistance. 109 Dec 97

A cloned DNA fragment from Anabaena sp. strain PCC 7120 that complements an arginine auxotrophic mutant from the same organism was found to include an open reading frame encoding a 427-residue polypeptide that is homologous to N-acetylornithine aminotransferase from Bacillus subtilis, Escherichia coli, and Saccharomyces cerevisiae. The gene encoding N-acetylornithine aminotransferase in bacteria has been named argD. The expression of Anabaena sp. strain PCC 7120 argD, as well as of argC, was analyzed at the mRNA level. Both genes were transcribed as monocistronic mRNAs, and their expression was not affected by exogenously added arginine. Primer extension analysis identified transcription start points for both genes which were preceded by sequences similar to that of the E. coli RNA polymerase sigma 70 consensus promoter. A second transcription start point for the argD gene that is not preceded by a sigma 70 consensus promoter was detected in dinitrogen-grown cultures.
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PMID:Analysis of expression of the argC and argD genes in the cyanobacterium Anabaena sp. strain PCC 7120. 792 12