1w9r

From Proteopedia

Revision as of 13:41, 21 February 2008

SOLUTION STRUCTURE OF CHOLINE BINDING PROTEIN A, DOMAIN R2, THE MAJOR ADHESIN OF STREPTOCOCCUS PNEUMONIAE

Overview

Streptococcus pneumoniae (pneumococcus) remains a significant health threat worldwide, especially to the young and old. While some of the biomolecules involved in pneumococcal pathogenesis are known and understood in mechanistic terms, little is known about the molecular details of bacterium/host interactions. We report here the solution structure of the 'repeated' adhesion domains (domains R1 and R2) of the principal pneumococcal adhesin, choline binding protein A (CbpA). Further, we provide insights into the mechanism by which CbpA binds its human receptor, polymeric immunoglobulin receptor (pIgR). The R domains, comprised of 12 imperfect copies of the leucine zipper heptad motif, adopt a unique 3-alpha-helix, raft-like structure. Each pair of alpha-helices is antiparallel and conserved residues in the loop between Helices 1 and 2 exhibit a novel 'tyrosine fork' structure that is involved in binding pIgR. This and other structural features that we show are conserved in most pneumococcal strains appear to generally play an important role in bacterial adhesion to pIgR. Interestingly, pneumococcus is the only bacterium known to adhere to and invade human cells by binding to pIgR.

About this Structure

1W9R is a Single protein structure of sequence from Streptococcus pneumoniae. Full crystallographic information is available from OCA.

Reference

Solution structure of choline binding protein A, the major adhesin of Streptococcus pneumoniae., Luo R, Mann B, Lewis WS, Rowe A, Heath R, Stewart ML, Hamburger AE, Sivakolundu S, Lacy ER, Bjorkman PJ, Tuomanen E, Kriwacki RW, EMBO J. 2005 Jan 12;24(1):34-43. Epub 2004 Dec 16. PMID:15616594

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