3LFP

Crystal Structure of the Restriction-Modification Controller Protein C.Csp231I

Summary for 3LFP

• Entry DOI: 10.2210/pdb3lfp/pdb
• Descriptor: Csp231I C protein (2 entities in total)
• Functional Keywords: transcriptional regulator, dna binding protein, helix-turn-helix, restriction-modification, transcription
• Biological source: Citrobacter sp. RFL231
• Total number of polymer chains: 1
• Total formula weight: 11380.24

Authors

McGeehan, J.E.,Streeter, S.D.,Thresh, S.J.,Kneale, G.G. (deposition date: 2010-01-18, release date: 2011-02-02, Last modification date: 2023-09-06)

Primary citation

McGeehan, J.E.,Streeter, S.D.,Thresh, S.J.,Taylor, J.E.,Shevtsov, M.B.,Kneale, G.G.
Structural Analysis of a Novel Class of R-M Controller Proteins: C.Csp231I from Citrobacter sp. RFL231.
J.Mol.Biol., 409:177-188, 2011

PubMed Abstract: Controller proteins play a key role in the temporal regulation of gene expression in bacterial restriction-modification (R-M) systems and are important mediators of horizontal gene transfer. They form the basis of a highly cooperative, concentration-dependent genetic switch involved in both activation and repression of R-M genes. Here we present biophysical, biochemical, and high-resolution structural analysis of a novel class of controller proteins, exemplified by C.Csp231I. In contrast to all previously solved C-protein structures, each protein subunit has two extra helices at the C-terminus, which play a large part in maintaining the dimer interface. The DNA binding site of the protein is also novel, having largely AAAA tracts between the palindromic recognition half-sites, suggesting tight bending of the DNA. The protein structure shows an unusual positively charged surface that could form the basis for wrapping the DNA completely around the C-protein dimer.

PubMed: 21440553
DOI: 10.1016/j.jmb.2011.03.033

Experimental method

X-RAY DIFFRACTION (2 Å)