Structural analysis of a novel class of R-M controller proteins: C.Csp231I from Citrobacter sp. RFL231

John McGeehan, Simon Streeter, Sarah Thresh, J. Taylor, Misha Shevtsov, Geoff Kneale

Research output: Contribution to journalArticlepeer-review

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.
Original languageEnglish
Pages (from-to)177-188
Number of pages12
JournalJournal of Molecular Biology
Volume409
Issue number2
DOIs
Publication statusPublished - 2011

Fingerprint

Dive into the research topics of 'Structural analysis of a novel class of R-M controller proteins: C.Csp231I from Citrobacter sp. RFL231'. Together they form a unique fingerprint.

Cite this