Organic anion transporters of the Major Facilitator Superfamily of transporters
Organic anion transporters (OATs) generally display broad substrate specificity and they facilitate the exchange of extracellular with intracellular organic anions (OAs). Several OATs have been characterized including OAT1-10 and urate anion exchanger 1 (URAT1, also called SLC22A12). Many OATs occur in renal proximal tubules, the site of active drug secretion. OATs mediate the absorption, distribution, and excretion of a diverse array of environmental toxins, and clinically important drugs, including anti-HIV therapeutics, anti-tumor drugs, antibiotics, anti-hypertensives, and anti-inflammatories, and therefore is critical for the survival of the mammalian species. OAT falls into the SLC22 (solute carrier 22) family of the Major Facilitator Superfamily (MFS) of membrane transport proteins, which 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]
Evidence:
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