Type: | Family | Name: | Bile acid:sodium symporter/arsenical resistance protein Acr3 |
Description: | This family of proteins are found both in prokaryotes and eukaryotes. They are related to the human bile acid:sodium symporters (TC 2.A.28), which are transmembrane proteins functioning in the liver in the uptake of bile acids from portal blood plasma, a process mediated by the co-transport of Na+[].This entry also includes members of the ACR3 family of arsenite (As(III)) permeases, which confer resistance to arsenic by extrusion from cells []. They exist in prokaryotes and eukaryotes (lower plants and fungi) [, ]. The ACR3 permeases have ten-transmembrane span topology []. Corynebacterium glutamicum has three Acr3 proteins, CgAcr3-1, CgAcr3-2, and CgAcr3-3. CgAcr3-1 is thought to be an antiporter that catalyses arsenite-proton exchange [].The Shewanella oneidensis Acr3 is not able to transport As(III) and confers resistance only to arsenate (As(V)) [], whereas the Acr3 orthologue from Synechocystis mediates tolerance to As(III), As(V) and antimonite (Sb(III)) [].In budding yeast, overexpression of the Acr3 gene confers an arsenite- but not an arsenate-resistance phenotype []. Saccharomyces cerevisiae Acr3 is a plasma membrane metalloid/H+ antiporter that transports arsenite and antimonite []. | Short Name: | BilAc:Na_symport/Acr3 |