3ONX
Crystal structure of a domain of a protein involved in formation of actin cytoskeleton
Summary for 3ONX
| Entry DOI | 10.2210/pdb3onx/pdb |
| Related | 3OKQ |
| Descriptor | Bud site selection protein 6 (1 entity in total) |
| Functional Keywords | coiled-coil, protein binding |
| Biological source | Saccharomyces cerevisiae (brewer's yeast,lager beer yeast,yeast) |
| Total number of polymer chains | 2 |
| Total formula weight | 32992.35 |
| Authors | |
| Primary citation | Tu, D.,Graziano, B.R.,Park, E.,Zheng, W.,Li, Y.,Goode, B.L.,Eck, M.J. Structure of the formin-interaction domain of the actin nucleation-promoting factor Bud6. Proc.Natl.Acad.Sci.USA, 109:E3424-E3433, 2012 Cited by PubMed Abstract: Formin proteins and their associated factors cooperate to assemble unbranched actin filaments in diverse cellular structures. The Saccharomyces cerevisiae formin Bni1 and its associated nucleation-promoting factor (NPF) Bud6 generate actin cables and mediate polarized cell growth. Bud6 binds to both the tail of the formin and G-actin, thereby recruiting monomeric actin to the formin to create a nucleation seed. Here, we structurally and functionally dissect the nucleation-promoting C-terminal region of Bud6 into a Bni1-binding "core" domain and a G-actin binding "flank" domain. The ∼2-Å resolution crystal structure of the Bud6 core domain reveals an elongated dimeric rod with a unique fold resembling a triple-helical coiled-coil. Binding and actin-assembly assays show that conserved residues on the surface of this domain mediate binding to Bni1 and are required for NPF activity. We find that the Bni1 dimer binds two Bud6 dimers and that the Bud6 flank binds a single G-actin molecule. These findings suggest a model in which a Bni1/Bud6 complex with a 2:4 subunit stoichiometry assembles a nucleation seed with Bud6 coordinating up to four actin subunits. PubMed: 23161908DOI: 10.1073/pnas.1203035109 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.904 Å) |
Structure validation
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