<p>The actin filament system, a prominent part of the cytoskeleton in eukaryotic cells, is both a static structure and a dynamic network that can undergo rearrangements: it is thought to be involved in processes such as cell movement and phagocytosis [<cite idref="PUB00002626"/>], as well as muscle contraction.</p><p>The F-actin capping protein binds in a calcium-independent manner to the fast growing ends of actin filaments (barbed end) thereby blocking the exchange of subunits at these ends. Unlike gelsolin (see <db_xref db="INTERPRO" dbkey="IPR007122"/>) and severin this protein does not sever actin filaments. The F-actin capping protein is a heterodimer composed of two unrelated subunits: alpha and beta. Neither of the subunits shows sequence similarity to other filament-capping proteins [<cite idref="PUB00002626"/>].</p><p>The beta-subunit is a protein of about 280 amino acid residues whose sequence is well conserved in eukaryotic species [<cite idref="PUB00004059"/>]. The signature pattern in this entry is a conserved hexapeptide in the N-terminal region of the beta-subunit.</p> F-actin capping protein, beta subunit, conserved site