1UPG

Crystal structure of the quorum-sensing protein TraM from Agrobacterium tumefaciens

Summary for 1UPG

• Entry DOI: 10.2210/pdb1upg/pdb
• Related: 1US6
• Descriptor: TRANSCRIPTIONAL REPRESSOR TRAM (2 entities in total)
• Functional Keywords: transcription repressor, negative regulator, quorum-sensing, conjugation, transcription regulation, repressor
• Biological source: AGROBACTERIUM TUMEFACIENS
• Total number of polymer chains: 2
• Total formula weight: 23111.78

Authors

Vannini, A.,Di Marco, S. (deposition date: 2003-09-30, release date: 2004-05-25, Last modification date: 2024-11-20)

Primary citation

Vannini, A.,Volpari, C.,Di Marco, S.
Crystal Structure of the Quorum-Sensing Protein Tram and its Interaction with the Transcriptional Regulator Trar
J.Biol.Chem., 279:24291-, 2004

PubMed Abstract: 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.

PubMed: 15044488
DOI: 10.1074/JBC.M401855200

Experimental method

X-RAY DIFFRACTION (1.8 Å)