Crystal Structure of Arp2/3 ComplexRobinson, R.C., Turbedsky, K., Kaiser, D.A., Marchand, J.-B., Higgs, H.N., Choe, S., Pollard, T.D.
(2001) Science 294: 1679-1684
- PubMed: 11721045
- DOI: https://doi.org/10.1126/science.1066333
- Primary Citation of Related Structures:
- PubMed 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.
Structural Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.