Eukaryotic Solute carrier 46 (SLC46) family, Bacterial Tetracycline resistance proteins, and similar proteins of the Major Facilitator Superfamily of transporters
This family is composed of the eukaryotic proteins MFSD9, MFSD10, MFSD14, and SLC46 family proteins, as well as bacterial multidrug resistance (MDR) transporters such as tetracycline resistance protein TetA and multidrug resistance protein MdtG. MDR transporters are drug/H+ antiporters (DHA) that mediate the efflux of a variety of drugs and toxic compounds, and confer resistance to these compounds. TetA proteins confer resistance to tetracycline while MdtG confers resistance to fosfomycin and deoxycholate. The Solute carrier 46 (SLC46) family is composed of three vertebrate members (SLC46A1, SLC46A2, and SLC46A3), the best-studied of which is SLC46A1, which functions both as an intestinal proton-coupled high-affinity folate transporter involved in the absorption of folates and as an intestinal heme transporter which mediates heme uptake. MFSD10 facilitates the uptake of organic anions such as some non-steroidal anti-inflammatory drugs (NSAIDs) and confers resistance to such NSAIDs. The SLC46/TetA-like 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.",