2p9i
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Crystal Structure of bovine Arp2/3 Complex co-crystallized with ADP and crosslinked with gluteraldehyde
OverviewOverview
ATP is required for nucleation of actin filament branches by Arp2/3, complex, but the influence of ATP binding and hydrolysis are poorly, understood. We determined crystal structures of bovine Arp2/3 complex, cocrystallized with various bound adenine nucleotides and cations., Nucleotide binding favors closure of the nucleotide-binding cleft of Arp3, but no large-scale conformational changes in the complex. Thus, ATP, binding does not directly activate Arp2/3 complex but is part of a network, of interactions that contribute to nucleation. We compared, nucleotide-induced conformational changes of residues lining the cleft in, Arp3 and actin structures to construct a movie depicting the proposed, ATPase cycle for the actin family. Chemical crosslinking stabilized, subdomain 1 of Arp2, revealing new electron density for 69 residues in, this subdomain. Steric clashes with Arp3 appear to be responsible for, intrinsic disorder of subdomains 1 and 2 of Arp2 in inactive Arp2/3, complex.
About this StructureAbout this Structure
2P9I is a Protein complex structure of sequences from Bos taurus with CA and ADP as ligands. Full crystallographic information is available from OCA.
ReferenceReference
Insights into the Influence of Nucleotides on Actin Family Proteins from Seven Structures of Arp2/3 Complex., Nolen BJ, Pollard TD, Mol Cell. 2007 May 11;26(3):449-457. PMID:17499050
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