Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have cloned and analysed the arcA gene which encodes a transcriptional activator necessary for the high-level expression of two genes for enzymes of the arginine catabolic pathway in Aspergillus nidulans: agaA (for arginase) and otaA (for ornithine transaminase, OTAse). Here we present complete genomic and cDNA sequences for, and describe the pattern of expression of, the arcA gene. This gene contains one intron and encodes a polypeptide of 600 amino acids. The deduced protein belongs to the family of Zn(2)Cys(6) fungal regulatory proteins. ARCA is the first known protein of this family that has glycine instead of the conserved proline at the fifth position in the second, six-residue, loop of the Zn cluster domain. We have established that transcription of the arcA gene is not self-regulated and does not depend on arginine. Two mutations in arcA, one gain-of-function and one loss-of-function, have been sequenced and the effects of these mutations on the expression of the agaA gene at the transcriptional level are reported.
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PMID:arcA, the regulatory gene for the arginine catabolic pathway in Aspergillus nidulans. 1181 Feb 30

The gamma-glutamyl-phosphate reductase (ProA) interlinks both the anabolic and osmostress adaptive proline biosynthetic routes of Bacillus subtilis. Because no paralogous protein to ProA exists in this microorganism, proA mutants should exhibit a tight proline auxotrophic growth phenotype. Contrary to expectations, proA mutants formed microcolonies on agar plates lacking proline and faster growing Pro(+) suppressor mutants arose. These mutants carried alterations in the rocR-rocDEF region encoding enzymes of the arginine degradation pathway and its transcriptional activator RocR. They were of two types: (i) mutants carrying single amino acid substitutions in RocR resulting in partial inducer-independent variants and (ii) mutants carrying single base-pair changes in the vicinity of the SigL/Sig-54-dependent -12/-24 class rocDEF promoter that activate a cryptic SigA-type promoter. Consequently, enhanced rocDEF transcription should lead to increased cellular amounts of the RocD ornithine aminotransferase, an enzyme that synthesizes the same reaction product as ProA, gamma-glutamic-semialdehyde/delta-1-pyrroline-5-carboxylate. This compound can be enzymatically converted into proline. The Pro(+) suppressors also exhibited a new regulatory pattern by allowing enhanced rocDEF transcription in response to proline availability when ammonium is present. Our work provides an example how flexibly bacteria can genetically develop routes to bypass constraints imposed on their biosynthetic networks and evolve new regulatory mechanisms.
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PMID:Mutational activation of the RocR activator and of a cryptic rocDEF promoter bypass loss of the initial steps of proline biosynthesis in Bacillus subtilis. 2386 54