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Background
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A global transcription regulator. Complexes with cyclic AMP (cAMP) which allosterically activates DNA binding (to consensus sequence 5'-AAATGTGATCTAGATCACATTT-3') to directly regulate the transcription of about 300 genes in about 200 operons and indirectly regulate the expression of about half the genome. There are 3 classes of CRP promoters, class I promoters have a single CRP- upstream of the RNA polymerase (RNAP)-, whereas in class II promoters the single CRP- and RNAP- overlap, CRP making multiple contacts with RNAP. Class III promoters require multiple activator molecules, including at least one CRP dimer. It can act as an activator, repressor, coactivator or corepressor. Induces a severe bend in DNA (about 87 degrees), bringing upstream promoter elements into contact with RNAP. Acts as a negative regulator of its own synthesis as well as for adenylate cyclase (cyaA), which generates cAMP. High levels of active CRP are detrimental to growth.Plays a major role in carbon catabolite repression (CCR). CCR involves cAMP, adenylate cyclase (cyaA), CRP and the EIIA-Glc component of the PTS (crr). In the presence of glucose EIIA-Glc is dephosphorylated, and does not activate adenylate cyclase, leading to reduced cAMP and thus decreased CRP activity. Also plays a role in many other processes
Synonyms: Catabolite activator protein,CAP,Catabolite gene activator,cAMP receptor protein,CRP,cAMP regulatory protein,crp,cap, csm,b3357, JW5702
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