Pept1

This entry represents the major facilitator superfamily (MFS) domain, which consists of twelve transmembrane helices. MFS proteins are the largest group of secondary membrane transporters in the cell. Among the different families of transporters, only two occur ubiquitously in all classifications of organisms; these are the ATP-Binding Cassette (ABC) superfamily 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 []. The MFS family contains members that function as uniporters, symporters or antiporters. In addition their solute specificity are also diverse. MFS proteins contain 12 transmembrane regions (with some variations).

This domain can be found in glycerol-3-phosphate transporter from Escherichia coli, which transports glycerol-3-phosphate into the cytoplasm and inorganic phosphate into the periplasm []. The E. coli proton/sugar transporter lactose permease (LacY) also carries this domain, and acts to couple lactose and H+ translocation [].

This entry represents the POT (proton-dependent oligopeptide transport) family, which all appear to be proton dependent transporters. The transport of peptides into cells is a well-documented biological phenomenon which is accomplished by specific, energy-dependent transporters found in a number of organisms as diverse as bacteria and humans. The POT family of proteins is distinct from the ABC-type peptide transporters and was uncovered by sequence analyses of a number of recently discovered peptide transport proteins []. These proteins that seem to be mainly involved in the intake of small peptides with the concomitant uptake of a proton [].

These integral membrane proteins are predicted to comprise twelve transmembrane regions.

The transport of peptides into cells is a well-documented biological phenomenon which is accomplished by specific, energy-dependent transporters found in a number of organisms as diverse as bacteria and humans. The PTR family of proteins is distinct from the ABC-type peptide transporters and was uncovered by sequence analyses of a number of recently discovered peptide transport proteins []. These proteins that seem to be mainly involved in the intake of small peptides with the concomitant uptake of a proton [].

These integral membrane proteins are predicted to comprise twelve transmembrane regions.

This entry describes two conserved sites. The first conserved site is found within a region that includes the end of the second transmembrane region, a cytoplasmic loop as well as the third transmembrane region. The second conserved site corresponds to the core of the fifth transmembrane region.

Oligopeptide transporter, peptide:H+ symporter supports the proton-coupled intake of oligopeptides of 2 to 4 amino acids. These proteins may constitute a major route for the absorption of the end products of protein digestion.