Major Facilitator Superfamily; The Major Facilitator Superfamily (MFS) is a large and diverse group of secondary transporters that includes uniporters, symporters, and antiporters. MFS proteins facilitate the transport across cytoplasmic or internal membranes of a variety of substrates including ions, sugar phosphates, drugs, neurotransmitters, nucleosides, amino acids, and peptides. They do so using the electrochemical potential of the transported substrates. Uniporters transport a single substrate, while symporters and antiporters transport two substrates in the same or in opposite directions, respectively, across membranes. MFS proteins are typically 400 to 600 amino acids in length, and the majority contain 12 transmembrane alpha helices (TMs) connected by hydrophilic loops. The N- and C-terminal halves of these proteins display weak similarity and may be the result of a gene duplication/fusion event. Based on kinetic studies and the structures of a few bacterial superfamily members, GlpT (glycerol-3-phosphate transporter), LacY (lactose permease), and EmrD (multidrug transporter), MFS proteins are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement. Bacterial members function primarily for nutrient uptake, and as drug-efflux pumps to confer antibiotic resistance. Some MFS proteins have medical significance in humans such as the glucose transporter Glut4, which is impaired in type II diabetes, and glucose-6-phosphate transporter (G6PT), which causes glycogen storage disease when mutated.

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gi 2217362764 192 GDNASNCDCRAWDYGIRAGLVQNVVSK 218
Cdd:cd17444     1 TENASSCQCTERDYRIRAGLVQNIVSK 27

Solute carrier family 22, member 23 of the Major Facilitator Superfamily; Solute carrier family 22, member 23 (SLC22A23) is an orphan member of the SLC22 family of organic cation/anion/zwitterion transporters, which includes organic cation transporters (OCTs/OCTNs) and organic anion transporters (OATs). It is abundantly expressed in brain and is also found in liver. Single-nucleotide polymorphisms in SLC22A23 are associated with inflammatory bowel disease (IBD) in a Canadian white population. SLC22 transporters interact with a variety of compounds that include drugs of abuse, environmental toxins, opioid analgesics, antidepressant and anxiolytic agents, and neurotransmitters and their metabolites. SLC22A23 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.

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gi 2217362764 192 GDNASNCDCRAWDYGIRAGLVQNVVSK 218
Cdd:cd17444     1 TENASSCQCTERDYRIRAGLVQNIVSK 27

Solute carrier family 22, member 23 of the Major Facilitator Superfamily; Solute carrier family 22, member 23 (SLC22A23) is an orphan member of the SLC22 family of organic cation/anion/zwitterion transporters, which includes organic cation transporters (OCTs/OCTNs) and organic anion transporters (OATs). It is abundantly expressed in brain and is also found in liver. Single-nucleotide polymorphisms in SLC22A23 are associated with inflammatory bowel disease (IBD) in a Canadian white population. SLC22 transporters interact with a variety of compounds that include drugs of abuse, environmental toxins, opioid analgesics, antidepressant and anxiolytic agents, and neurotransmitters and their metabolites. SLC22A23 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.

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                  ....*....|....*....|....*..
gi 2217362764 192 GDNASNCDCRAWDYGIRAGLVQNVVSK 218
Cdd:cd17444     1 TENASSCQCTERDYRIRAGLVQNIVSK 27