Protein unc-93 homolog A and similar proteins of the Major Facilitator Superfamily of transporters
This subfamily is composed of Caenorhabditis elegans Uncoordinated protein 93 (also called putative potassium channel regulatory protein unc-93), human protein unc-93 homolog A (HmUnc-93A or UNC93A), and similar proteins. Unc-93 acts as a regulatory subunit of a multi-subunit potassium channel complex that may function in coordinating muscle contraction in C. elegans. The human UNC93A gene is located in a region of the genome that is frequently associated with ovarian cancer, however, there is no evidence that UNC93A has a tumor suppressor function. This unc93A-like subfamily belongs to the Unc-93 family of the Major Facilitator Superfamily (MFS) of transporters. MFS proteins 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.",