Optometry Research Today is a free monthly online journal that collates and summarizes the latest research about Optometry, including details on myopia, optometric practice, therapy.

A 'Collagen Hug' model for Staphylococcus aureus CNA binding to collagen.

Zong Y, Xu Y, Liang X, Keene DR, Höök A, Gurusiddappa S, Höök M, Narayana SV

School of Optometry and Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA.

The structural basis for the association of eukaryotic and prokaryotic protein receptors and their triple-helical collagen ligand remains poorly understood. Here, we present the crystal structures of a high affinity subsegment of the Staphylococcus aureus collagen-binding CNA as an apo-protein and in complex with a synthetic collagen-like triple helical peptide. The apo-protein structure is composed of two subdomains (N1 and N2), each adopting a variant IgG-fold, and a long linker that connects N1 and N2. The structure is stabilized by hydrophobic inter-domain interactions and by the N2 C-terminal extension that complements a beta-sheet on N1. In the ligand complex, the collagen-like peptide penetrates through a spherical hole formed by the two subdomains and the N1-N2 linker. Based on these two structures we propose a dynamic, multistep binding model, called the 'Collagen Hug' that is uniquely designed to allow multidomain collagen binding proteins to bind their extended rope-like ligand.

Published 21 December 2005 in EMBO J, 24(24): 4224-36.
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