Macrolide efflux protein A and similar proteins of the Major Facilitator Superfamily of transporters
This family is composed of Streptococcus pyogenes macrolide efflux protein A (MefA) and similar transporters, many of which remain uncharacterized. Some members may be multidrug resistance (MDR) transporters, which are drug/H+ antiporters (DHAs) that mediate the efflux of a variety of drugs and toxic compounds, conferring resistance to these compounds. MefA confers resistance to 14-membered macrolides including erythromycin and to 15-membered macrolides. It functions as an efflux pump to regulate intracellular macrolide levels. The MefA-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.",