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Publication Abstract from PubMed

In Bacillus subtilis, the termination of DNA replication via polar fork arrest is effected by a specific protein:DNA complex formed between the replication terminator protein (RTP) and DNA terminator sites. We report the crystal structure of a replication terminator protein homologue (RTP.C110S) of B. subtilis in complex with the high affinity component of one of its cognate DNA termination sites, known as the TerI B-site, refined at 2.5 A resolution. The 21 bp RTP:DNA complex displays marked structural asymmetry in both the homodimeric protein and the DNA. This is in contrast to the previously reported complex formed with a symmetrical TerI B-site homologue. The induced asymmetry is consistent with the complex's solution properties as determined using NMR spectroscopy. Concomitant with this asymmetry is variation in the protein:DNA binding pattern for each of the subunits of the RTP homodimer. It is proposed that the asymmetric "wing" positions, as well as other asymmetrical features of the RTP:DNA complex, are critical for the cooperative binding that underlies the mechanism of polar fork arrest at the complete terminator site.

An asymmetric structure of the Bacillus subtilis replication terminator protein in complex with DNA.,Vivian JP, Porter CJ, Wilce JA, Wilce MC J Mol Biol. 2007 Jul 13;370(3):481-91. Epub 2007 Mar 2. PMID:17521668^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.