<p>The actin-depolymerising factor homology (ADF-H) domain is an ~150-amino acid motif that is present in three phylogenetically distinct classes of eukaryotic actin-binding proteins [<cite idref="PUB00043718"/>, <cite idref="PUB00022142"/>, <cite idref="PUB00043719"/>]:</p><p> <ul> <li>ADF/cofilins, which include ADF, cofilin, destrin, actophorin, coactosin, depactin and glia maturation factors (GMFs) beta and gamma. ADF/cofilins are small actin-binding proteins composed of a single ADF-H domain. They bind both actin-monomers and filaments and promote rapid filament turnover in cells by depolymerising/fragmenting actin filaments. ADF/cofilins bind ADP-actin with higher affinity than ATP-actin and inhibit the spontaneous nucleotide exchange on actin monomers</li> <li> Twinfilins, which are actin monomer-binding proteins that are composed of two ADF-H domains</li> <li>Abp1/Drebrins, which are relatively large proteins composed of an N-terminal ADF-H domain followed by a variable region and a C-terminal SH3 domain. Abp1/Drebrins interact only with actin filaments and do not promote filament depolymerisation or fragmentation</li></ul> </p><p>Although these proteins are biochemically distinct and play different roles in actin dynamics, they all appear to use the ADF-H domain for their interactions with actin.</p><p>The ADF-H domain consists of a six-stranded mixed beta-sheet in which the four central strands (beta2-beta5) are anti-parallel and the two edge strands (beta1 and beta6) run parallel with the neighbouring strands. The sheet is surrounded by two alpha-helices on each side [<cite idref="PUB00043718"/>, <cite idref="PUB00022142"/>, <cite idref="PUB00031293"/>].</p><p>This entry represents a subgroup containing the ADF-H domain and found in ADF proteins, cofilins and destrins.</p> ADF/Cofilin/Destrin