4bj3

Publication Abstract from PubMed

The GFOGER motif in collagens (O denotes hydroxyproline) represents a high-affinity binding site for all collagen-binding integrins. Other GxOGER motifs require integrin activation for maximal binding. The E318W mutant of the integrin alpha2beta1 I domain displays a relaxed collagen specificity, typical of an active state. E318W binds more strongly than the wild-type alpha2 I domain to GMOGER, and forms a 2:1 complex with a homotrimeric, collagen-like, GFOGER peptide. Crystal structure analysis of this complex reveals two E318W I domains, A and B, bound to a single triple helix. The E318W I domains are virtually identical to the collagen-bound wild-type I domain, suggesting that the E318W mutation activates the I domain by destabilising the unligated conformation. E318W I domain A interacts with two collagen chains similarly to wild-type I domain (high-affinity mode). E318W I domain B makes favourable interactions with only one collagen chain (low-affinity mode). This observation suggests that single GxOGER motifs in the heterotrimeric collagens V and IX may support binding of activated integrins.

An activating mutation reveals a second binding mode of the integrin alpha2 I domain to the GFOGER motif in collagens.,Carafoli F, Hamaia SW, Bihan D, Hohenester E, Farndale RW PLoS One. 2013 Jul 29;8(7):e69833. doi: 10.1371/journal.pone.0069833. Print 2013. PMID:23922814^[1]

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