| Primary Identifier | IPR039672 | Type | Family |
| Short Name | MFS_2 |
| description | This family includes lactose permease (LacY) and its homologues that are members of the sodium:galactoside symporter (TC 2.A.2) family. LacY is found in Firmicute bacteria such as Streptococcus thermophilus, and is required for transport of beta-galactosides into the cell. Cations are co-transported. LacY contains a PTS EIIA type-1 domain, which may be regulatory. It is an integral membrane protein with many transmembrane regions []. Other homologues in this family include the melibiose carrier protein (MelB) from Escherichia coli, which is required for the transport of melibiose and other galactosides []; glucuronide carrier protein (UidB or GusB), also from E.coli, which transports glucuronide (but is inactive in some strains) []; and isoprimeverose transporter (XylP) from Lactobacillus pentosus, which transports isoprimeverose []. A human member of this family, MFSD12, has been recently characterised as a transporter that mediates the import of cysteine into melanosomes, thereby regulating skin pigmentation []. In melanosomes, cysteine import is required both for normal levels of cystine, the oxidized dimer of cysteine, and provide cysteine for the production of the cysteinyldopas used in pheomelanin synthesis, thereby regulating skin pigmentation []. In non-pigmented cells, it catalyses the import of cysteine into lysosomes []. |
