Crystal structure of Arp2/3 complex

Science. 2001 Nov 23;294(5547):1679-84. doi: 10.1126/science.1066333.

Abstract

We determined a crystal structure of bovine Arp2/3 complex, an assembly of seven proteins that initiates actin polymerization in eukaryotic cells, at 2.0 angstrom resolution. Actin-related protein 2 (Arp2) and Arp3 are folded like actin, with distinctive surface features. Subunits ARPC2 p34 and ARPC4 p20 in the core of the complex associate through long carboxyl-terminal alpha helices and have similarly folded amino-terminal alpha/beta domains. ARPC1 p40 is a seven-blade beta propeller with an insertion that may associate with the side of an actin filament. ARPC3 p21 and ARPC5 p16 are globular alpha-helical subunits. We predict that WASp/Scar proteins activate Arp2/3 complex by bringing Arp2 into proximity with Arp3 for nucleation of a branch on the side of a preexisting actin filament.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actin Cytoskeleton / chemistry*
  • Actin Cytoskeleton / metabolism*
  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actins / chemistry*
  • Actins / metabolism*
  • Adenosine Triphosphate / metabolism
  • Animals
  • Cattle
  • Crystallography, X-Ray
  • Cytoskeletal Proteins*
  • Macromolecular Substances
  • Models, Biological
  • Models, Molecular
  • Muscle, Skeletal
  • Protein Structure, Quaternary
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Protein Subunits
  • Static Electricity
  • Thymus Gland

Substances

  • Actin-Related Protein 2
  • Actin-Related Protein 3
  • Actins
  • Cytoskeletal Proteins
  • Macromolecular Substances
  • Protein Subunits
  • Adenosine Triphosphate

Associated data

  • PDB/1K8K