PDBsum entry 2emt

Cell adhesion

PDB id: 2emt

Contents

Protein chains

313 a.a.

16 a.a.

17 a.a.

Ligands

LYS-THR-HIS-MET-TYR-PRO-VAL-ARG-ASN

References listed in PDB file

Key reference

• Title: Structural basis of psgl-1 binding to erm proteins.
• Authors: Y.Takai, K.Kitano, S.Terawaki, R.Maesaki, T.Hakoshima.
• Ref.: Genes Cells, 2007, 12, 1329-1338.
• PubMed id: 18076570

Abstract

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.

Secondary reference #1

• Title: Crystallographic characterization of the radixin ferm domain bound to the cytoplasmic tails of adhesion molecules cd43 and psgl-1.
• Authors: Y.Takai, K.Kitano, S.Terawaki, R.Maesaki, T.Hakoshima.
• Ref.: Acta Crystallogr Sect F Struct Biol Cryst Commun, 2007, 63, 49-51.
• PubMed id: 17183174