f Cra-mediated regulation of Escherichia coli adenylate cyclase
- Authors: Martine Crasnier-Mednansky†, Maxwell C. Park, William K. Studley, Milton H. Saier Jr
- *Author for correspondence: Martine Crasnier-Mednansky. Tel: + 1 619 534 2457. Fax: + 1 619 534 7108. e-mail: firstname.lastname@example.org
- First Published Online: 01 March 1997, Microbiology 143: 785-792, doi: 10.1099/00221287-143-3-785
- Subject: Physiology And Growth
- Issue Published:
In Escherichia coli, expression of certain genes and operons, including the fructose operon, is controlled by Cra, the pleiotropic catabolite repressor/activator protein formerly known as FruR. In this study we have demonstrated that cra mutant strains synthesize 10-fold less cAMP than isogenic wild-type strains, specifically when grown in fructose-containing minimal media. The glucose-specific IIA protein (IIAglc) of the phosphotransferase system, which activates adenylate cyclase when phosphorylated, is largely dephosphorylated in cra but not wild-type strains growing under these conditions. Dephosphorylation of IIAglcin cra strains apparently results from enhanced fructose operon transcription and fructose uptake. These conclusions were supported by showing that fructose-grown cra strains possess 2.5-fold higher fructose-1-phosphate kinase activity than fructose-grown wild-type strains. Moreover, artificially increasing fructose operon expression in cells transporting fructose dramatically decreased the activity of adenylate cyclase. The results establish that Cra indirectly regulates the activity of adenylate cyclase by controlling the expression of the fructose operon in cells growing with fructose as the sole carbon source.
Present address: On sabbatical leave from the Centre National de la Recherche Scientifique, UnitéA AssociéAe 1129, Institut Pasteur, 28 rue du Docteur Roux, 75724 Paris cedex 15, France.
- Keyword(s): adenylate cyclase, phosphotransferase system, catabolite repressor/activator protein, fructose operon, Escherichia coli
© Society for General Microbiology 1997 | Published by the Microbiology Society
Article metrics loading...
Full text loading...
Author and Article Information
/content/journal/micro/10.1099/00221287-143-3-785dcterms_title,dcterms_subject,pub_serialTitlepub_serialIdent:journal/micro AND -contentType:BlogPost104
/content/journal/micro/10.1099/00221287-143-3-785dcterms_title,dcterms_subject-pub_serialIdent:journal/micro AND -contentType:BlogPost104
Figure data loading....