Download MendeleyStructure of a Bud6/Actin Complex Reveals a Novel WH2-like Actin Monomer Recruitment Motif.
Park, E., Graziano, B.R., Zheng, W., Garabedian, M., Goode, B.L., Eck, M.J.(2015) Structure 23: 1492-1499
- PubMed: 26118535
- DOI: https://doi.org/10.1016/j.str.2015.05.015
- Primary Citation of Related Structures:
4WYB - PubMed Abstract:
In budding yeast, the actin-binding protein Bud6 cooperates with formins Bni1 and Bnr1 to catalyze the assembly of actin filaments. The nucleation-enhancing activity of Bud6 requires both a "core" domain that binds to the formin and a "flank" domain that binds monomeric actin. Here, we describe the structure of the Bud6 flank domain in complex with actin. Two helices in Bud6(flank) interact with actin; one binds in a groove at the barbed end of the actin monomer in a manner closely resembling the helix of WH2 domains, a motif found in many actin nucleation factors. The second helix rises along the face of actin. Mutational analysis verifies the importance of these Bud6-actin contacts for nucleation-enhancing activity. The Bud6 binding site on actin overlaps with that of the formin FH2 domain and is also incompatible with inter-subunit contacts in F-actin, suggesting that Bud6 interacts only transiently with actin monomers during filament nucleation.
Organizational Affiliation:
Department of Cancer Biology, Dana-Farber Cancer Institute, SM1036, 450 Brookline Avenue, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02215, USA.
