help button home button Genetics J Bacteriology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fandl, J. P.
Right arrow Articles by Artz, S. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fandl, J. P.
Right arrow Articles by Artz, S. W.

Genetics, Vol 125, 719-727, Copyright © 1990

INVESTIGATIONS

Mutations That Affect Transcription and Cyclic AMP-CRP Regulation of the Adenylate Cyclase Gene (cya) of Salmonella typhimurium

J. P. Fandl, L. K. Thorner and S. W. Artz
Present address: Regeneron Pharmaceuticals, Inc., Suite 10, 777 Old Saw Mill River Road, Tarrytown, New York 10591.

We studied the expression of the cya promoter(s) in cya-lac fusion strains of Salmonella typhimurium and demonstrated cAMP receptor protein (CRP)-dependent repression by cAMP. Expression of cya was reduced about fourfold in cultures grown in acetate minimal medium as compared to cultures grown in glucose-6-phosphate minimal medium. Expression of cya was also reduced about fourfold by addition of 5 mM cAMP to cultures grown in glucose minimal medium. We constructed in vitro deletion and insertion mutations altering a major cya promoter (P2) and a putative CRP binding site overlapping P2. These mutations were recombined into the chromosome by allele replacement with M13mp::cya recombinant phages and the regulation of the mutant promoters was analyzed. A 4-bp deletion of the CRP binding site and a 4-bp insertion in this site nearly eliminated repression by cAMP. A mutant with the P2 promoter and the CRP binding site both deleted exhibited an 80% reduction in cya expression; the 20% residual expression was insensitive to cAMP repression. This mutant retained a Cya(+) phenotype. Taken together, the results establish that the cya gene is transcribed from multiple promoters one of which, P2, is negatively regulated by the cAMP-CRP complex. Correction for the contribution to transcription by the cAMP-CRP nonregulated cya promoters indicates that the P2 promoter is repressed at least eightfold by cAMP-CRP.


This article has been cited by other articles:


Home page
 Microbiol. Mol. Biol. Rev.Home page
J. Deutscher, C. Francke, and P. W. Postma
How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria
Microbiol. Mol. Biol. Rev., December 1, 2006; 70(4): 939 - 1031.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1990 by the Genetics Society of America.