Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.10.2 (focal adhesion kinase)
 44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The carAB operon, encoding carbamoylphosphate synthetase (CPSase; EC 6.3.5.5) is transcribed from two tandem promoters. The upstream promoter (P1) is controlled by pyrimidines and the downstream promoter (P2) is controlled by arginine. We have isolated a new type of constitutive mutation (carP) that specifically affects the control of the pyrimidine-sensitive promoter but does not appear to influence other genes of the pyrimidine pathway. The carP mutation acts in trans and is dominant, which suggests that the carP product is an activator of car transcription. The downstream promoter P2, which is repressed by arginine, overlaps two operator modules characteristic of the arginine regulon. We have isolated two operator-constitutive mutations that specifically affect P2; both map in the upstream ARG box at a strongly conserved position.
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PMID:carP, a novel gene regulating the transcription of the carbamoylphosphate synthetase operon of Escherichia coli. 306 18

The control region of the carAB operon, encoding carbamoylphosphate synthetase, comprises two tandem promoters (P1, upstream and P2, downstream) located 67 base-pairs apart and repressed respectively by pyrimidines and arginine. RNA polymerase and pure arginine repressor bind to the P2 region in mutually exclusive ways. Repressor protects the two adjacent palindromic ARG boxes overlapping P2 against DNase I. Binding of RNA polymerase to P1 is abnormal; the region protected against DNase I is shifted upstream by about 20 nucleotides with respect to the position expected from the transcription startpoint. This pattern is not due to interference with polymerase binding at P2, since it is observed also in the presence of repressor and on an isolated P1 region. Binding of RNA polymerase is relatively weak and heparin-sensitive suggesting that, in vivo, an ancillary factor is required to promote the formation of an open complex. S1 nuclease mapping experiments show that the simultaneous presence of pyrimidines and arginine represses the downstream arginine-specific promoter (P2) more efficiently than arginine alone. This effect is not due to a direct regulatory interaction between pyrimidines and P2, since it is not observed when P1 is inactivated by insertion mutations or partial deletion. It has been shown that transcription initiated at P1 can proceed even when arginine represses P2. We therefore suggest that P2 operator-arginine repressor complex is destabilized by RNA polymerase binding at P1 or transcription from P1. We describe a novel technique to select for expression-down mutants in a lac fusion context.
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PMID:Molecular interactions in the control region of the carAB operon encoding Escherichia coli carbamoylphosphate synthetase. 306 19