2emt
From Proteopedia
Crystal Structure Analysis of the radixin FERM domain complexed with adhesion molecule PSGL-1
Overview
P-selectin glycoprotein ligand-1 (PSGL-1), an adhesion molecule with O-glycosylated extracellular sialomucins, is involved in leukocyte inflammatory responses. On activation, ezrin-radixin-moesin (ERM) proteins mediate the redistribution of PSGL-1 on polarized cell surfaces to facilitate binding to target molecules. ERM proteins recognize a short binding motif, Motif-1, conserved in cytoplasmic tails of adhesion molecules, whereas PSGL-1 lacks Motif-1 residues important for binding to ERM proteins. The crystal structure of the complex between the radixin FERM domain and a PSGL-1 juxtamembrane peptide reveals that the peptide binds the groove of FERM subdomain C by forming a beta-strand associated with strand beta5C, followed by a loop flipped out towards the solvent. The Motif-1 3(10) helix present in the FERM-ICAM-2 complex is absent in PSGL-1 given the absence of a critical Motif-1 alanine residue, and PSGL-1 reduces its contact area with subdomain C. Non-conserved positions are occupied by large residues Met9 and His8, which stabilize peptide conformation and enhance groove binding. Non-conserved residues play an important role in compensating for loss of binding energy resulting from the absence of conserved residues important for binding.
About this Structure
2EMT is a Protein complex structure of sequences from Mus musculus. Full crystallographic information is available from OCA.
Reference
Structural basis of PSGL-1 binding to ERM proteins., Takai Y, Kitano K, Terawaki S, Maesaki R, Hakoshima T, Genes Cells. 2007 Dec;12(12):1329-38. PMID:18076570 Page seeded by OCA on Sun May 4 02:48:12 2008
