Na+/Melibiose Membrane Transport Protein, MelB
Living reference work entry
Melibiose permease (MelB) is encoded by the melB gene in the melAB operon, which is present in many Gram-negative bacteria. MelB belongs to the glycoside–pentoside–hexuronide:cation symporter (GPH) family (TC 2.A.2) of the major facilitator superfamily (MFS). MelB catalyzes the transport of di- or trisaccharides containing a d-galactopyranosyl ring or galactose, and the native substrate is melibiose, a disaccharide formed by an α-1,6 linkage between galactose and glucose ( d-Gal-α(1 → 6)- d-Glc) (Fig. 1). It can be also formed by invertase-mediated hydrolysis of raffinose, which produces one melibiose and one fructose.
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- Hariharan P, Guan L (2017) Thermodynamic cooperativity of cosubstrate binding and cation selectivity of Salmonella typhimurium MelB. J Gen Physiol. https://doi.org/10.1085/jgp.201711788
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