PDBsum entry 4jd2

Structural protein

PDB id: 4jd2

Contents

Protein chains

398 a.a.

377 a.a.

342 a.a.

283 a.a.

170 a.a.

166 a.a.

139 a.a.

138 a.a.

Ligands

ATP ×2

PG4 ×2

Metals

_CA ×2

References listed in PDB file

Key reference

• Title: Structural basis for regulation of arp2/3 complex by gmf.
• Authors: Q.Luan, B.J.Nolen.
• Ref.: Nat Struct Biol, 2013, 20, 1062-1068. [DOI no: 10.1038/nsmb.2628]
• PubMed id: 23893131

Abstract

The Arp2/3 complex mediates formation of complex cellular structures such as lamellipodia by nucleating branched actin filaments. Arp2/3-complex activity is precisely controlled by over a dozen regulators, yet the structural mechanism by which regulators interact with the complex is unknown. GMF is a recently discovered regulator of the Arp2/3 complex that can inhibit nucleation and disassemble branches. We solved the structure of the 240-kDa assembly of Mus musculus GMF and Bos taurus Arp2/3 complex and found that GMF binds the barbed end of Arp2, overlapping with the proposed binding site of WASP-family proteins. The structure suggests that GMF can bind branch junctions in the manner that cofilin binds filament sides, consistent with a modified cofilin-like mechanism for debranching by GMF. The GMF-Arp2 interface reveals how the ADF-H actin-binding domain in GMF is exploited to specifically recognize Arp2/3 complex and not actin.