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 1676316604  11 CWIGMFFSSIGMSQIAPILPLYIKQLGVTDVSLIQQYSGIIFGCTFVVAAFFSPI 65
Cdd:cd17391     1 CWLGNFFTGIGFSLIAPFLPLYIEQLGVTSGGLVELWSGLAFSSTFLVSAIFSPI 55

Multidrug resistance protein MdtG and similar multidrug resistance (MDR) transporters of the Major Facilitator Superfamily; This subfamily is composed of Escherichia coli multidrug resistance protein MdtG, Streptococcus pneumoniae multidrug resistance efflux pump PmrA, and similar multidrug resistance (MDR) transporters from bacteria. 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. MdtG confers resistance to fosfomycin and deoxycholate. PmrA serves as an efflux pump for various substrates and is associated with fluoroquinolone resistance. MdtG-like MDR transporters belong to the bacterial MdtG-like and eukaryotic solute carrier 18 (SLC18) 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.

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gi 1676316604  11 CWIGMFFSSIGMSQIAPILPLYIKQLGVTDVSLIQQYSGIIFGCTFVVAAFFSPI 65
Cdd:cd17391     1 CWLGNFFTGIGFSLIAPFLPLYIEQLGVTSGGLVELWSGLAFSSTFLVSAIFSPI 55

Multidrug resistance protein MdtG and similar multidrug resistance (MDR) transporters of the Major Facilitator Superfamily; This subfamily is composed of Escherichia coli multidrug resistance protein MdtG, Streptococcus pneumoniae multidrug resistance efflux pump PmrA, and similar multidrug resistance (MDR) transporters from bacteria. 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. MdtG confers resistance to fosfomycin and deoxycholate. PmrA serves as an efflux pump for various substrates and is associated with fluoroquinolone resistance. MdtG-like MDR transporters belong to the bacterial MdtG-like and eukaryotic solute carrier 18 (SLC18) 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.

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gi 1676316604  11 CWIGMFFSSIGMSQIAPILPLYIKQLGVTDVSLIQQYSGIIFGCTFVVAAFFSPI 65
Cdd:cd17391     1 CWLGNFFTGIGFSLIAPFLPLYIEQLGVTSGGLVELWSGLAFSSTFLVSAIFSPI 55

bacterial MdtG-like and eukaryotic solute carrier 18 (SLC18) family of the Major Facilitator Superfamily of transporters; This family is composed of eukaryotic solute carrier 18 (SLC18) family transporters and related bacterial multidrug resistance (MDR) transporters including several proteins from Escherichia coli such as multidrug resistance protein MdtG, from Bacillus subtilis such as multidrug resistance proteins 1 (Bmr1) and 2 (Bmr2), and from Staphylococcus aureus such as quinolone resistance protein NorA. The family also includes Escherichia coli arabinose efflux transporters YfcJ and YhhS. 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. The SLC18 transporter family includes vesicular monoamine transporters (VAT1 and VAT2), vesicular acetylcholine transporter (VAChT), and SLC18B1, which is proposed to be a vesicular polyamine transporter (VPAT). The MdtG/SLC18 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.

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gi 1676316604  11 CWIGMFFSSIGMSQIAPILPLYIKQLGVTDVSLiqqysGIIFGCTFVVAAFFSPI 65
Cdd:cd17325     1 LSLALFLDMLGYGIIIPILPLYAESLGASVAQI-----GLIVAAYALAQLLFSPP 50