P-galac-tosidase activities were determined in a constitutively derepressed crp mutant background in order to quantitate promoter activities independent of regulation by CAMP-CRP -LRB- the results were unaffected by addition of CAMP-data not shown -RRB- .
Therefore , overproduction of cAMP by crp mutants must be the indirect consequence of a defect in CRP-mediated regulation of adenylate cyclase activity rather thancya expression , a conclusion .
Therefore , overproduction of cAMP by crp mutants must be the direct consequence of a defect in CRP-mediated regulation of adenylate cyclase activity rather thancya expression , a conclusion .
Mechanism of the down-regulation of cAMP-receptor-protein by glucose in Escherichia coli : role of autoregulation of the crp gene .
One possible route would be regulation of crp by SdsR , for CRP-deficient Salmonella display altered susceptibility to antibiotic challenge .