DNA sequence of the carA gene and the control region of carAB: tandem promoters, respectively controlled by arginine and the pyrimidines, regulate the synthesis of carbamoyl-phosphate synthetase in Escherichia coli K-12

Proc Natl Acad Sci U S A. 1984 Jul;81(13):4134-8. doi: 10.1073/pnas.81.13.4134.

Abstract

The carAB operon of Escherichia coli K-12, which encodes the two subunits of carbamoyl-phosphate synthetase (glutamine hydrolyzing) [carbon-dioxide: L-glutamine amido-ligase (ADP-forming, carbamate-phosphorylating); EC 6.3.5.5], is cumulatively repressed by arginine and the pyrimidines. We describe the structure of the control region of carAB and the sequence of the carA gene. Nuclease S1 mapping experiments show that two adjacent tandem promoters within the carAB control region serve as initiation sites. The upstream promoter P1 is controlled by pyrimidines; the downstream promoter P2 is regulated by arginine. Attenuation control does not appear to be involved in the expression of carAB. A possible mechanism by which control at these promoters concurs to produce a cumulative pattern of repression is discussed. The translational start of carA is atypical; it consists of a UUG or AUU codon.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arginine / pharmacology*
  • Base Sequence
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / biosynthesis
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / genetics*
  • Cloning, Molecular
  • DNA Restriction Enzymes
  • Enzyme Repression
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Genes* / drug effects
  • Genes, Bacterial* / drug effects
  • Ligases / genetics*
  • Operon* / drug effects
  • Pyrimidines / pharmacology*
  • Transcription, Genetic

Substances

  • Pyrimidines
  • Arginine
  • DNA Restriction Enzymes
  • Ligases
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)

Associated data

  • GENBANK/J01597