Lysine 100 acetylation effect of CRP (catabolite activator protein) in gene expression in Escherichia coli

cAMP receptor protein (CRP, also known as the catabolite activator protein [CAP]) is arguably the best-studied of the global transcription factors of E coli. CRP alone is responsible for regulating at least 283 operons. Upon binding cAMP, the CRP dimer binds DNA and directly interacts with RNA polymerase (RNAP). At Class II promoters, CRP binds near position -41,5 relative to the transcription start site and contacts the amino-terminal domain of the RNAP subunit (RNAP-NTD). This interaction requires AR2, a patch of primarily positively charged residues (H19, H21, E96, and K101) that interact with negatively charged residues on RNAP-NTD. Acetylome analyses consistently detect lysine 100 (K100) of CRP as acetylated. Since K100 is adjacent to the positively charged AR2, we hypothesized that the K100 positive charge may also play a role in CRP function. We further hypothesized that acetylation of K100 would neutralize this positive charge, leading to a potential regulatory mechanism

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Guebel DV, Torres NV