Molecular and functional characterization of a carbon starvation gene of Escherichia coli.
Escherichia coli induces the synthesis of at least 30 proteins at the onset of carbon starvation, two-thirds of which are positively regulated by the cyclic AMP (cAMP) and cAMP receptor protein (CRP) complex. Two of the cAMP-CRP-dependent genes mapped to 14 and 93 minutes of the chromosome and are designated cstA and cstB, respectively. The cstA promoter region was cloned and localized to a 600 base-pair fragment downstream from the iron-regulated entCEBA-P15 operon. Carbon starvation-inducible transcription initiated at three sites spaced one turn of the DNA helix apart. All had--10 sequences similar to consensus E sigma 70 promoters and poor--35 sequences. Deletion of a putative CRP binding site abolished carbon starvation-mediated induction. Sequence analysis of the cstA coding region revealed the presence of three sequential open reading frames potentially encoding two hydrophobic proteins of 60,223 Da and 15,201 Da and a hydrophilic protein of 7467 Da. Overexpression of the cstA region produced starvation-inducible proteins of the expected sizes. Suggestive evidence was obtained that cstA is involved in peptide utilization.
Schultz
J E
JE
Department of Microbiology and Immunology, Stanford University School of Medicine, CA 94305-5402.
Matin
A
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D002244:Carbon / Q000378:metabolism*; D002876:Chromosomes, Bacterial; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D005798:Genes, Bacterial; D005838:Genotype; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010957:Plasmids; D011487:Protein Conformation; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014161:Transduction, Genetic
D001426:Bacterial Proteins; D002373:Cyclic AMP Receptor Protein; D004269:DNA, Bacterial; D002244:Carbon