Tandemly repeated domains found in gelsolin, severin, villin, and related proteins.
Gelsolin repeats occur in gelsolin, severin, villin, advillin, villidin, supervillin, flightless, quail, fragmin, and other proteins, usually in several copies. They co-occur with villin headpiece domains, leucine-rich repeats, and several other domains. These gelsolin-related actin binding proteins (GRABPs) play regulatory roles in the assembly and disassembly of actin filaments; they are involved in F-actin capping, uncapping, severing, or the nucleation of actin filaments. Severing of actin filaments is Ca2+ dependent. Villins are also linked to generating bundles of F-actin with uniform filament polarity, which is most likely mediated by their extra villin headpiece domain. Many family members have also adopted functions in the nucleus, including the regulation of transcription. Supervillin, gelsolin, and flightless I are involved in intracellular signaling via nuclear hormone receptors. The gelsolin-like domain is distantly related to the actin depolymerizing domains found in cofilin and similar proteins.
Feature 1: putative type 2 Ca binding site [ion binding site], 2 residue positions
Conserved feature residue pattern:D E
Evidence:
Comment:Activated actin-bound gelsolin has eight Ca2+-binding sites: six type-2 sites, one in each sub-domain, and two type 1 sites, associated with the first and the fourth sub-domain.
Comment:not all members of this subfamily may bind calcium at this site
Structure:1SVY: the second sub-domain of Dictyostelium discoideum severin binds Ca2+ in a type 2 binding site
Jiyao W et al.(2023). "The conserved domain database in 2023.",