Family 2.A.60 - The Organo Anion Transporter Family       

Family ID: 52641

Proteins of the OAT family catalyze the Na+-independent facilitated transport of organic anions such as bromosulfobromophthalein and prostaglandins as well as conjugated and unconjugated bile acids (taurocholate and cholate, respectively). These transporters have been characterized in mammals, but homologues are present in C. elegans and A. thaliana. Some of the mammalian proteins exhibit a high degree of tissue specificity. For example, the rat OAT is found at high levels in liver and kidney and at lower levels in other tissues. These proteins consist of 600-700 amino acyl residues and possess 10-12 putative a-helical transmembrane spanners. They may catalyze electrogenic anion uniport or anion exchange.

A phylogenetic tree of some members of the family shows several mammalian anion transporters clustering together, but the prostaglandin transporters and the LST anion transporters cluster seperately. PSI-BLAST results with a single iteration indicate that the OAT family is a distant family within the MFS (TC #2.A.1).