Solute carrier family 37 member 4 of the Major Facilitator Superfamily of transporters
Solute carrier family 37 member 4 (SLC37A4), one of four SLC37 family proteins in vertebrates, is better known as glucose-6-phosphate transporter (G6PT). It is also called sugar phosphate exchanger 4 (SPX4), G6P translocase, or transformation-related gene 19 protein (TRG-19). G6PT is a phosphate (Pi)-linked G6P antiporter, catalyzing G6P:Pi and Pi:Pi exchanges. Deficiencies in human G6PT lead to glycogen storage disease type Ib (GSD-Ib), which is a metabolic and immune disorder. G6PT is a member of the Organophosphate:Pi antiporter (OPA)/SLC37 family, whose members are integral membrane proteins responsible for the transport of specific organophosphates or sugar phosphates across biological membranes with the simultaneous translocation of inorganic phosphate into the opposite direction. The OPA/SLC37 family 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
Jiyao W et al.(2023). "The conserved domain database in 2023.",