Catabolite activator protein–DNA complex (CAP–DNA)

The Catabolite activator protein–DNA complex (CAP–DNA complex) is a fundamental regulatory assembly in prokaryotic gene expression, primarily characterized in Escherichia coli (UniProt: P0ACJ8) [1]. The complex forms when the Catabolite Activator Protein (CAP), also known as the cAMP Receptor Protein (CRP), binds to its allosteric effector, cyclic AMP (cAMP), which induces a conformational change allowing the protein to bind specifically to DNA sequences [2]. This binding results in a significant bending of the DNA, often exceeding 90 degrees, which is a critical step for the recruitment and activation of RNA polymerase at various promoters (PDB: 1CGP) [3]. The CAP–DNA complex is the central mediator of carbon catabolite repression, a mechanism that enables bacteria to prioritize the utilization of glucose over other carbon sources [4]. Beyond its metabolic role, CAP-like proteins regulate the expression of virulence factors in several human pathogens, including Vibrio cholerae and Mycobacterium tuberculosis, making the complex a potential target for the development of novel antimicrobial therapies [5]. Research into this complex has provided foundational insights into the principles of allosteric regulation and protein-DNA recognition in molecular biology [2, 3]. Citations: [1] UniProt P0ACJ8; [2] Busby & Ebright (1999) J Mol Biol; [3] Schultz et al. (1991) Science; [4] Gorke & Stulke (2008) Nat Rev Microbiol; [5] Rickman et al. (2005) Mol Microbiol.

Other names

cAMP receptor protein–DNA complexCRP–DNA complexCatabolite gene activator protein–DNA complexCAP-DNA complexCatabolite activator proteincAMP receptor protein

Competitive inhibition of cAMP binding or allosteric modulation of DNA binding affinity