Solute carrier family 22, member 17 and similar proteins of the Major Facilitator Superfamily
This group is composed of Solute carrier family 22, members 17, 23, and 31. They are members of the SLC22 family of organic cation/anion/zwitterion transporters, which includes organic cation transporters (OCTs/OCTNs) and organic anion transporters (OATs). SLC22A17 functions as a cell surface receptor for lipocalin-2 (LCN2), also called NGAL or 24p3, which plays a key role in iron homeostasis and transport. SLC22A23 and SLC22A31 are orphan members of the SLC22 family. SLC22 transporters interact with a variety of compounds that include drugs of abuse, environmental toxins, opioid analgesics, antidepressant and anxiolytic agents, and neurotransmitters and their metabolites. The SLC22A17-like group belongs to 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