1g6n
From Proteopedia
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2.1 ANGSTROM STRUCTURE OF CAP-CAMP
Overview
After an allosteric transition produced by the binding of cyclic AMP (cAMP), the Escherichia coli catabolite gene activator protein (CAP) binds DNA specifically and activates transcription. The three-dimensional crystal structure of the CAP-cAMP complex has been refined at 2.1 A resolution, thus enabling a better evaluation of the structural basis for CAP phenotypes, the interactions of cAMP with CAP and the roles played by water structure. A review of mutational analysis of CAP together with the additional structural information presented here suggests a possible mechanism for the cAMP-induced allostery required for DNA binding and transcriptional activation. We hypothesize that cAMP binding may reorient the coiled-coil C-helices, which provide most of the dimer interface, thereby altering the relative positions of the DNA-binding domains of the CAP dimer. Additionally, cAMP binding may cause a further rearrangement of the DNA-binding and cAMP-binding domains of CAP via a flap consisting of beta-strands 4 and 5 which lies over the cAMP.
About this Structure
1G6N is a Single protein structure of sequence from Escherichia coli with as ligand. This structure supersedes the now removed PDB entries 3GAP and 1GAP. Full crystallographic information is available from OCA.
Reference
Modeling the cAMP-induced allosteric transition using the crystal structure of CAP-cAMP at 2.1 A resolution., Passner JM, Schultz SC, Steitz TA, J Mol Biol. 2000 Dec 15;304(5):847-59. PMID:11124031
Page seeded by OCA on Thu Feb 21 12:46:45 2008
