Monocarboxylate transporter 1 of the Major Facilitator Superfamily of transporters
Monocarboxylate transporter 1 (MCT1) is also called Solute carrier family 16 member 1 (SLC16A1). It is a proton-coupled transporter that facilitates the transport across the plasma membrane of monocarboxylates such as lactate, pyruvate, branched-chain oxo acids derived from leucine, valine and isoleucine, and ketone bodies such as acetoacetate, beta-hydroxybutyrate and acetate. It is widely expressed in many tissues its main function is to transport lactate into the cell. MCT1 deficiency has been identified as a cause of profound ketoacidosis, a potentially lethal condition caused by the imbalance between hepatic production and extrahepatic utilization of ketone bodies. This suggests that MCT1-mediated ketone-body transport is crucial in maintaining acid-base balance. MCT1 belongs to the Monocarboxylate transporter (MCT) family of the Major Facilitator Superfamily (MFS) of membrane transport proteins. 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.",