PMID: 17401189 , Related PDB id: 2JCG

Authors:

Singh RK, Palm GJ, Panjikar S, Hinrichs W

Title:

Structure of the apo form of the catabolite control protein A (CcpA) from Bacillus megaterium with a DNA-binding domain.

Journal:

Acta Crystallogr Sect F Struct Biol Cryst Commun. 2007 Apr 1;63(Pt, 4):253-7. Epub 2007 Mar 12.

Abstract:

Crystal structure determination of catabolite control protein A (CcpA) at 2.6 A resolution reveals for the first time the structure of a full-length apo-form LacI-GalR family repressor protein. In the crystal structures of these transcription regulators, the three-helix bundle of the DNA-binding domain has only been observed in cognate DNA complexes; it has not been observed in other crystal structures owing to its mobility. In the crystal packing of apo-CcpA, the protein-protein contacts between the N-terminal three-helix bundle and the core domain consisted of interactions between the homodimers that were similar to those between the corepressor protein HPr and the CcpA N-subdomain in the ternary DNA complex. In contrast to the DNA complex, the apo-CcpA structure reveals large subdomain movements in the core, resulting in a complete loss of contacts between the N-subdomains of the homodimer.