3K8U

Crystal Structure of the Peptidase Domain of Streptococcus ComA, a Bi-functional ABC Transporter Involved in Quorum Sensing Pathway

Summary for 3K8U

• Entry DOI: 10.2210/pdb3k8u/pdb
• Descriptor: Putative ABC transporter, ATP-binding protein ComA (2 entities in total)
• Functional Keywords: abc transporter, coma, cysteine protease, quorum-sensing, streptococcus, hydrolase
• Biological source: Streptococcus mutans
• Total number of polymer chains: 1
• Total formula weight: 17992.57

Authors

Ishii, S.,Yano, T.,Ebihara, A.,Okamoto, A.,Manzoku, M.,Hayashi, H. (deposition date: 2009-10-14, release date: 2010-02-23, Last modification date: 2024-03-20)

Primary citation

Ishii, S.,Yano, T.,Ebihara, A.,Okamoto, A.,Manzoku, M.,Hayashi, H.
Crystal structure of the peptidase domain of Streptococcus ComA, a bifunctional ATP-binding cassette transporter involved in the quorum-sensing pathway
J.Biol.Chem., 285:10777-10785, 2010

PubMed Abstract: ComA of Streptococcus is a member of the bacteriocin-associated ATP-binding cassette transporter family and is postulated to be responsible for both the processing of the propeptide ComC and secretion of the mature quorum-sensing signal. The 150-amino acid peptidase domain (PEP) of ComA specifically recognizes an extended region of ComC that is 15 amino acids in length. It has been proposed that an amphipathic alpha-helix formed by the N-terminal leader region of ComC, as well as the Gly-Gly motif at the cleavage site, is critical for the PEP-ComC interaction. To elucidate the substrate recognition mechanism, we determined the three-dimensional crystal structure of Streptococcus mutans PEP and then constructed models for the PEP.ComC complexes. PEP had an overall structure similar to the papain-like cysteine proteases as has long been predicted. The active site was located at the bottom of a narrow cleft, which is suitable for binding the Gly-Gly motif. Together with the results from mutational experiments, a shallow hydrophobic concave surface of PEP was proposed as a site that accommodates the N-terminal helix of ComC. This dual mode of substrate recognition would provide the small PEP domain with an extremely high substrate specificity.

PubMed: 20100826
DOI: 10.1074/jbc.M109.093781

Experimental method

X-RAY DIFFRACTION (1.9 Å)