1UX5

Crystal Structures of a Formin Homology-2 domain reveal a flexibly tethered dimer architecture

Summary for 1UX5

• Entry DOI: 10.2210/pdb1ux5/pdb
• Related: 1UX4
• Descriptor: BNI1 PROTEIN (2 entities in total)
• Functional Keywords: structural protein, fh2 actin cytoskeleton
• Biological source: SACCHAROMYCES CEREVISIAE (BAKER'S YEAST)
• Total number of polymer chains: 1
• Total formula weight: 47395.86

Authors

Xu, Y.,Moseley, J.B.,Sagot, I.,Poy, F.,Pellman, D.,Goode, B.L.,Eck, M.J. (deposition date: 2004-02-19, release date: 2004-03-11, Last modification date: 2024-10-23)

Primary citation

Xu, Y.,Moseley, J.B.,Sagot, I.,Poy, F.,Pellman, D.,Goode, B.L.,Eck, M.J.
Crystal Structures of a Formin Homology-2 Domain Reveal a Tethered Dimer Architecture
Cell(Cambridge,Mass.), 116:711-, 2004

PubMed Abstract: Formin proteins participate in a wide range of cytoskeletal processes in all eukaryotes. The defining feature of formins is a highly conserved approximately 400 residue region, the Formin Homology-2 (FH2) domain, which has recently been found to nucleate actin filaments. Here we report crystal structures of the S. cerevesiae Bni1p FH2 domain. The mostly alpha-helical FH2 domain forms a unique "tethered dimer" in which two elongated actin binding heads are tied together at either end by an unusual lasso and linker structure. Biochemical and crystallographic observations indicate that the dimer is stable but flexible, with flexibility between the two halves of the dimer conferred by the linker segments. Although each half of the dimer is competent to interact with filament ends, the intact dimer is required for actin nucleation and processive capping. The tethered dimer architecture may allow formins to stair-step on the barbed end of an elongating nascent filament.

PubMed: 15006353
DOI: 10.1016/S0092-8674(04)00210-7

Experimental method

X-RAY DIFFRACTION (2.5 Å)