Domain of unknown function (DUF4838). This family consists of several uncharacterized proteins found in various Bacteroides and Chloroflexus species. The function of this family is unknown.
Glycosyl hydrolase family 67 N-terminus. Alpha-glucuronidases, components of an ensemble of enzymes central to the recycling of photosynthetic biomass, remove the alpha-1,2 linked 4-O-methyl glucuronic acid from xylans. This family represents the N-terminal region of alpha-glucuronidase. The N-terminal domain forms a two-layer sandwich, each layer being formed by a beta sheet of five strands. A further two helices form part of the interface with the central, catalytic, module (pfam07488).
Gelsolin sub-domain 5-like domain 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.