PROSITE documentation PDOC51444
Formin homology-2 (FH2) domain profile


Formin proteins participate in a wide range of cytoskeletal processes in all eukaryotes. They promote nucleation and elongation of the actin filament, and thus are key regulators for this process. The defining feature of formins is a highly conserved ~400 residue region, the Formin Homology-2 (FH2) domain, which forms a head-to-tail ring-shaped dimer, and directly binds to the actin filament at its barbed end. The FH2 domain catalyzes the nucleation and elongation of actin filament, preventing capping proteins from binding to the barbed end [1,2].

The FH2 domain is almost entirely α helical and can be subdivided into five subdomains with somewhat arbitrary boundaries. These include an N-terminal "lasso", a "linker" segment, a globular "knob" subdomain, a coiled-coil region, and a carboxy-terminal "post" subdomain (see <PDB:1UX5>)>. The dimer formation is mediated by unique interactions of "lasso" with "post" of the partner FH2, exhibiting a closed ring structure [1,2].

The profile we developed covers the entire FH2 domain.

Last update:

March 2009 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

FH2, PS51444; Formin homology-2 (FH2) domain profile  (MATRIX)


1AuthorsXu Y. Moseley J.B. Sagot I. Poy F. Pellman D. Goode B.L. Eck M.J.
TitleCrystal structures of a Formin Homology-2 domain reveal a tethered dimer architecture.
SourceCell 116:711-723(2004).
PubMed ID15006353

2AuthorsYamashita M. Higashi T. Suetsugu S. Sato Y. Ikeda T. Shirakawa R. Kita T. Takenawa T. Horiuchi H. Fukai S. Nureki O.
TitleCrystal structure of human DAAM1 formin homology 2 domain.
SourceGenes Cells 12:1255-1265(2007).
PubMed ID17986009

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