Cofilin, Destrin, and related actin depolymerizing factors. Actin depolymerization factor/cofilin-like domains (ADF domains) are present in a family of essential eukaryotic actin regulatory proteins. These proteins enhance the turnover rate of actin, and interact with actin monomers (G-actin) as well as actin filaments (F-actin), typically with a preference for ADP-G-actin subunits. The basic function of cofilin is to promote disassembly of aged actin filaments. Vertebrates have three isoforms of cofilin: cofilin-1 (Cfl1, non-muscle cofilin), cofilin-2 (muscle cofilin), and ADF (destrin). When bound to actin monomers, cofilins inhibit their spontaneous exchange of nucleotides. The cooperative binding to (aged) ADP-F-actin induces a local change in the actin filament structure and further promotes aging.

actin depolymerizing factor; Provisional

TRX family; composed of two groups: Group I, which includes proteins that exclusively encode a TRX domain; and Group II, which are composed of fusion proteins of TRX and additional domains. Group I TRX is a small ancient protein that alter the redox state of target proteins via the reversible oxidation of an active site dithiol, present in a CXXC motif, partially exposed at the protein's surface. TRX reduces protein disulfide bonds, resulting in a disulfide bond at its active site. Oxidized TRX is converted to the active form by TRX reductase, using reducing equivalents derived from either NADPH or ferredoxins. By altering their redox state, TRX regulates the functions of at least 30 target proteins, some of which are enzymes and transcription factors. It also plays an important role in the defense against oxidative stress by directly reducing hydrogen peroxide and certain radicals, and by serving as a reductant for peroxiredoxins. At least two major types of functional TRXs have been reported in most organisms; in eukaryotes, they are located in the cytoplasm and the mitochondria. Higher plants contain more types (at least 20 TRX genes have been detected in the genome of Arabidopsis thaliana), two of which (types f amd m) are located in the same compartment, the chloroplast. Also included in the alignment are TRX-like domains which show sequence homology to TRX but do not contain the redox active CXXC motif. Group II proteins, in addition to either a redox active TRX or a TRX-like domain, also contain additional domains, which may or may not possess homology to known proteins.

glycoside hydrolase family 47 protein; Provisional

Glycosyl hydrolase family 47. Members of this family are alpha-mannosidases that catalyze the hydrolysis of the terminal 1,2-linked alpha-D-mannose residues in the oligo-mannose oligosaccharide Man(9)(GlcNAc)(2).