Lactose permease (LacS) (LacS)

Lactobacillus reuteri LacS permease is a membrane-integrated transport protein belonging to the Glycoside-Pentoside-Hexuronide (GPH):Cation Symporter family (UniProt Consortium, 2023; TCDB, 2023). Its primary biological function is the translocation of lactose and other galactosides across the cytoplasmic membrane, which is essential for the energy metabolism of this probiotic bacterium (Saulnier et al., 2011). The permease typically operates through a symport mechanism with protons or via a precursor-product exchange mechanism, such as lactose/galactose antiport, allowing the cell to conserve metabolic energy (Poolman, 1993). While LacS is not a target for conventional therapeutic drugs, it is a key factor in the ecological fitness and survival of L. reuteri within the mammalian gastrointestinal tract (Zheng et al., 2020). By enabling the utilization of milk sugars, LacS supports the growth of beneficial microbiota, which can indirectly contribute to the management of lactose intolerance and the maintenance of gut homeostasis (Saulnier et al., 2011). Research into this transporter focuses on microbial physiology and the optimization of probiotic strains rather than direct pharmacological inhibition.

Other names

Galactoside permeaseLactose transport proteinLactose-proton symporterLactose:H+ symporterGPH permease

No known therapeutic drugs target this protein.