2P9N: Crystal Structure Of Bovine Arp2/3 Complex Co-crystallized With Adp

Citation:
Abstract
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.
PDB ID: 2P9NDownload
MMDB ID: 46537
PDB Deposition Date: 2007/3/26
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 2.85  Å
Source Organism:
Similar Structures:
Biological Unit for 2P9N: heptameric; determined by author and by software (PISA)
Molecular Components in 2P9N
Label Count Molecule
Proteins (7 molecules)
1
Actin-like Protein 3(Gene symbol: ACTR3)
Molecule annotation
1
Actin-like Protein 2(Gene symbol: ACTR2)
Molecule annotation
1
Actin-related Protein 2/3 Complex Subunit 1B(Gene symbol: ARPC1B)
Molecule annotation
1
Actin-related Protein 2/3 Complex Subunit 2(Gene symbol: ARPC2)
Molecule annotation
1
Actin-related Protein 2/3 Complex Subunit 3(Gene symbol: ARPC3)
Molecule annotation
1
Actin-related Protein 2/3 Complex Subunit 4(Gene symbol: ARPC4)
Molecule annotation
1
Actin-related Protein 2/3 Complex Subunit 5(Gene symbol: ARPC5)
Molecule annotation
Chemicals (3 molecules)
1
1
2
2
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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