3RSE
Structural and biochemical characterization of two binding sites for nucleation promoting factor WASp-VCA on Arp2/3 complex
Summary for 3RSE
| Entry DOI | 10.2210/pdb3rse/pdb |
| Descriptor | Actin-related protein 3, Actin-related protein 2, Actin-related protein 2/3 complex subunit 1B, ... (9 entities in total) |
| Functional Keywords | heteroheptamer, heptameric heterocomplex, f-actin branch initiation, actin, cytosol, structural protein |
| Biological source | Bos taurus More |
| Cellular location | Cytoplasm, cytoskeleton (By similarity): P61157 A7MB62 Q58CQ2 Q3MHR7 Q3T035 Q148J6 Q3SYX9 |
| Total number of polymer chains | 8 |
| Total formula weight | 224663.02 |
| Authors | Pollard, T.D.,Jurgenson, C.T.,Ti, S.,Nolen, B.J. (deposition date: 2011-05-02, release date: 2011-06-01, Last modification date: 2023-09-13) |
| Primary citation | Ti, S.C.,Jurgenson, C.T.,Nolen, B.J.,Pollard, T.D. Structural and biochemical characterization of two binding sites for nucleation-promoting factor WASp-VCA on Arp2/3 complex. Proc.Natl.Acad.Sci.USA, 108:E463-E471, 2011 Cited by PubMed Abstract: Actin-related protein (Arp) 2/3 complex mediates the formation of actin filament branches during endocytosis and at the leading edge of motile cells. The pathway of branch formation is ambiguous owing to uncertainty regarding the stoichiometry and location of VCA binding sites on Arp2/3 complex. Isothermal titration calorimetry showed that the CA motif from the C terminus of fission yeast WASP (Wsp1p) bound to fission yeast and bovine Arp2/3 complex with a stoichiometry of 2 to 1 and very different affinities for the two sites (K(d)s of 0.13 and 1.6 μM for fission yeast Arp2/3 complex). Equilibrium binding, kinetic, and cross-linking experiments showed that (i) CA at high-affinity site 1 inhibited Arp2/3 complex binding to actin filaments, (ii) low-affinity site 2 had a higher affinity for CA when Arp2/3 complex was bound to actin filaments, and (iii) Arp2/3 complex had a much higher affinity for free CA than VCA cross-linked to an actin monomer. Crystal structures showed the C terminus of CA bound to the low-affinity site 2 on Arp3 of bovine Arp2/3 complex. The C helix is likely to bind to the barbed end groove of Arp3 in a position for VCA to deliver the first actin subunit to the daughter filament. PubMed: 21676862DOI: 10.1073/pnas.1100125108 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.65 Å) |
Structure validation
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