PDBsum entry 2ynn

Protein transport

PDB id: 2ynn

Contents

Protein chain

300 a.a.

Ligands

CYS-THR-PHE-LYS-THR-LYS-THR-ASN

SO4 ×3

Waters ×231

References listed in PDB file

Key reference

• Title: Molecular basis for recognition of dilysine trafficking motifs by copi.
• Authors: L.P.Jackson, M.Lewis, H.M.Kent, M.A.Edeling, P.R.Evans, R.Duden, D.J.Owen.
• Ref.: Dev Cell, 2012, 23, 1255-1262.
• PubMed id: 23177648

Abstract

COPI mediates retrograde trafficking from the Golgi to the endoplasmic reticulum (ER) and within the Golgi stack, sorting transmembrane proteins bearing C-terminal KKxx or KxKxx motifs. The structure of KxKxx motifs bound to the N-terminal WD-repeat domain of β'-COP identifies electrostatic contacts between the motif and complementary patches at the center of the β'-COP propeller. An absolute requirement of a two-residue spacing between the terminal carboxylate group and first lysine residue results from interactions of carbonyl groups in the motif backbone with basic side chains of β'-COP. Similar interactions are proposed to mediate binding of KKxx motifs by the homologous α-COP domain. Mutation of key interacting residues in either domain or in their cognate motifs abolishes in vitro binding and results in mistrafficking of dilysine-containing cargo in yeast without compromising cell viability. Flexibility between β'-COP WD-repeat domains and the location of cargo binding have implications for COPI coat assembly.