In molecular biology, ADF-H domain (actin-depolymerising factor homology domain) is an approximately 150 amino acid

motif Motif may refer to: General concepts * Motif (chess composition), an element of a move in the consideration of its purpose * Motif (folkloristics), a recurring element that creates recognizable patterns in folklore and folk-art traditions * Moti ...

that is present in three

phylogenetically In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

distinct classes of eukaryotic

actin-binding protein Actin-binding proteins (also known as ABPs) are proteins that bind to actin. This may mean ability to bind actin monomers, or polymers, or both. Many actin-binding proteins, including α-actinin, β-spectrin, dystrophin, utrophin and fimbrin, do t ...

s. *ADF/cofilins, which include ADF, cofilin,

destrin Destrin or DSTN (also known as actin depolymerizing factor or ADF) is a protein which in humans is encoded by the ''DSTN'' gene. Destrin is a component protein in microfilaments. The product of this gene belongs to the actin-binding proteins A ...

, actophorin, coactosin, depactin and

glia maturation factor Glia maturation factor is a neurotrophic factor implicated in nervous system development, angiogenesis and immune function. In humans, the glia maturation factor beta and glia maturation factor gamma proteins are encoded by the ''GMFB'' and '' ...

s (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

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by depolymerising/fragmenting actin filaments. ADF/cofilins bind

ADP Adp or ADP may refer to: Aviation * Aéroports de Paris, airport authority for the Parisian region in France * Aeropuertos del Perú, airport operator for airports in northern Peru * SLAF Anuradhapura, an airport in Sri Lanka * Ampara Air ...

-actin with higher affinity than

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-actin and inhibit the spontaneous nucleotide exchange on actin monomers * Twinfilins, which are actin monomer-binding proteins that are composed of two ADF-H domains *Abp1/Drebrins, which are relatively large

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

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. 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. 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 .

References

{{InterPro content, IPR002108 Protein domains