@article{3141,
  abstract     = {The two actin-related subunits of the Arp2/3 complex, Arp2 and Arp3, are proposed to form a pseudo actin dimer that nucleates actin polymerization. However, in the crystal structure of the inactive complex, they are too far apart to form such a nucleus. Here, we show using EM that yeast and bovine Arp2/3 complexes exist in a distribution among open, intermediate and closed conformations. The crystal structure docks well into the open conformation. The activator WASp binds at the cleft between Arp2 and Arp3, and all WASp-bound complexes are closed. The inhibitor coronin binds near the p35 subunit, and all coronin-bound complexes are open. Activating and loss-of-function mutations in the p35 subunit skew conformational distribution in opposite directions, closed and open, respectively. We conclude that WASp stabilizes p35-dependent closure of the complex, holding Arp2 and Arp3 closer together to nucleate an actin filament.},
  author       = {Rodal, Avital A and Sokolova, Olga and Robins, Deborah B and Daugherty, Karen M and Simon Hippenmeyer and Riezman, Howard and Grigorieff, Nikolaus and Goode, Bruce L},
  journal      = {Nature Structural and Molecular Biology},
  number       = {1},
  pages        = {26 -- 31},
  publisher    = {Nature Publishing Group},
  title        = {{Conformational changes in the Arp2 3 complex leading to actin nucleation}},
  doi          = {10.1038/nsmb870},
  volume       = {12},
  year         = {2005},
}