H
IPR036259

MFS transporter superfamily

InterPro entry
Short nameMFS_trans_sf
Overlapping entries
 
Nodulin-like (IPR010658)

Description

This entry represents MFS transporter superfamily, characterized by twelve transmembrane helices. This superfamily includes, among others, the glycerol-3-phosphate transporter from Escherichia coli, which transports glycerol-3-phosphate into the cytoplasm and inorganic phosphate into the periplasm
[4]
, and the E. coli proton/sugar transporter lactose permease (LacY), which acts to couple lactose and H+ translocation
[5, 6]
.

Transporters can be grouped in two classes, primary and secondary carriers. The primary active transporters drive solute accumulation or extrusion by using ATP hydrolysis, photon absorption, electron flow, substrate decarboxylation or methyl transfer. If charged molecules are unidirectionally pumped as a consequence of the consumption of a primary cellular energy source, electron chemical potential results. This potential can than be used to drive the active transport of additional solutes via secondary carriers.

Among the different transporter the two largest families that occur ubiquitously in all classifications of organisms are the ATP-Binding Cassette (ABC) primary transporter superfamily (see
[prositedoc:PDOC00185]
) and the Major Facilitator Superfamily (MFS). The MFS transporters are single-polypeptide secondary carriers capable only of transporting small solutes in response to chemiosmotic ion gradients
[2, 3]
. They function as uniporters, symporters or antiporters. In addition their solute specificity are also diverse. MFS proteins contain 12 transmembrane regions (with some variations).

The 3D-structure of human GLUT1, an archetype of the major facilitator superfamily has been solved
[1]
. Helices 1-5, 8, 10-12 are arranged in a 9-member barrel-like manner, delimiting a hydrophilic central channel. Helix 7 is located in the centre of the channel suggesting a role in regulating transport of solutes through the channel.

References

1.[The prognostic value of chorionic-gonadotrophins in the urine of miscarrying women] Dykova H, Jirasek JE, Zwinger A, Krabec Z. 40, 417-20, (1975). PMID: 1157130

2.Major facilitator superfamily. Pao SS, Paulsen IT, Saier MH Jr. Microbiol. Mol. Biol. Rev. 62, 1-34, (1998). View articlePMID: 9529885

3.Sugar transporters from bacteria, parasites and mammals: structure-activity relationships. Walmsley AR, Barrett MP, Bringaud F, Gould GW. Trends Biochem. Sci. 23, 476-81, (1998). View articlePMID: 9868370

4.Structure and mechanism of the glycerol-3-phosphate transporter from Escherichia coli. Huang Y, Lemieux MJ, Song J, Auer M, Wang DN. Science 301, 616-20, (2003). View articlePMID: 12893936

5.Structure and mechanism of the lactose permease of Escherichia coli. Abramson J, Smirnova I, Kasho V, Verner G, Kaback HR, Iwata S. Science 301, 610-5, (2003). View articlePMID: 12893935

6.Structural evidence for induced fit and a mechanism for sugar/H+ symport in LacY. Mirza O, Guan L, Verner G, Iwata S, Kaback HR. EMBO J. 25, 1177-83, (2006). View articlePMID: 16525509

Cross References

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