1us6

Publication Abstract from PubMed

Transfer of the tumor-inducing plasmid in Agrobacterium tumefaciens is controlled by a quorum-sensing system whose main components are the transcriptional regulator TraR and its autoinducer. This system allows bacteria to synchronize infection of the host plant when a "quorum" of cells has been reached. TraM is an A. tumefaciens protein involved in the regulation of this system because it binds to TraR and prevents it from binding DNA. As a first step to understanding the molecular basis for the regulation of TraR by TraM, we have determined the crystal structure of TraM at 1.65 A resolution. This protein is packed as a dimer, with each monomer consisting mainly of two antiparallel alpha helices. Monomers are tightly associated, with a large hydrophobic area buried upon dimerization. Secondly, we characterized the TraR-TraM complex in vitro. TraM (11.4 kDa, monomer molecular mass) binds tightly TraR (27 kDa, monomer molecular mass) forming a stable oligomeric complex that likely accounts for two TraR and two TraM dimers.

Crystal structure of the quorum-sensing protein TraM and its interaction with the transcriptional regulator TraR.,Vannini A, Volpari C, Di Marco S J Biol Chem. 2004 Jun 4;279(23):24291-6. Epub 2004 Mar 24. PMID:15044488^[1]

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