Solute carrier organic anion transporter 3 family of the Major Facilitator Superfamily of transporters
The Solute carrier organic anion transporter 3 (SLCO3) or Organic anion transporting polypeptide 3 (OATP3) family contains only one subfamily, OATP3A, which contains only one mammalian member OATP3A1 (encoded by SLCO3A1). It mediates the Na(+)-independent transport of organic anions such as estrone-3-sulfate, prostaglandins (PG) E1 and E2, thyroxine (T4), deltorphin II, BQ-123, and vasopressin. SLCO3A1 has been identified as a Crohn's disease (CD)-associated gene, which mediates inflammatory processes in intestinal epithelial cells through NF-kappaB transcription activation, resulting in a higher incidence of bowel perforation in CD patients. The SLCO3/OATP3 family belongs to the Solute carrier organic anion transporter [SLCO, also called organic anion transporting polypeptides (OATPs) or Solute carrier family 21] family of the Major Facilitator Superfamily (MFS) of transporters. MFS proteins are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
Feature 1:putative chemical substrate binding pocket [chemical binding site]
Comment:based on the structures of MFS transporters with bound substrates, substrate analogs, and/or inhibitors
Comment:since MFS proteins facilitate the transport of many different substrates including ions, sugar phosphates, drugs, neurotransmitters, nucleosides, amino acids, and peptides, the residues involved in substrate binding may not be strictly conserved among superfamily members
Comment:the substrate binding site or translocation pore has access to both sides of the membrane in an alternating fashion through a conformational change of the MFS transporter