Disease relevance of mglB

• A novel aspect of the inhibition by arsenicals of binding-protein-dependent galactose transport in gram-negative bacteria [1].
• Galactose transport in Salmonella typhimurium [2].
• Thus, galactose transport in Escherichia coli could also be reconstituted by its respective binding protein [3].

High impact information on mglB

• The inhibition of binding-protein-dependent galactose transport by arsenite is probably linked to the inhibition by arsenite of the galactose-stimulated lipoamide dehydrogenase activity implicated in this transport and is reminiscent of the known arsenite inhibition of lipoamide dehydrogenases [1].
• The MglC/E proteins are devoid of ATPase activity and they complement an extract from a strain carrying a plasmid with the mglA gene for reconstitution of the MglB-dependent galactose transport in proteoliposomes [4].
• The high affinity galactose transport system of Salmonella typhimurium consists of four proteins, a periplasmic galactose binding protein (the MglB protein), and three inner membrane-associated proteins, the MglA, MglC and MglE proteins [4].
• In Salmonella typhimurium and Escherichia coli the high-affinity galactose transport system, which contains a periplasmic galactose-binding protein as an essential component, is encoded by the mgl genes [5].
• None of the other galactose transport systems, including methyl beta-D-thiogalactosides I and II, the beta-methyl-galactoside permease, and both arabinose systems, is able to catalyze transport of 2-deoxygalactose to a significant extent [6].

Biological context of mglB

• Lysogenization of an E. coli mutant carrying a defective galactose-binding protein with lambda gt7 mglB (Salmonella) restores full galactose transport and galactose chemotaxis [7].
• Galactose transport is coupled to ATP hydrolysis with a stoichiometry (ATP/galactose) of 2.5:1 [8].

Anatomical context of mglB

• The present reconstitution of galactose transport in proteoliposomes suggests that the MglA, MglC and MglE proteins have been solubilized and renatured in an active form from the inclusion bodies of the mgl hyperproducing strain [8].

Associations of mglB with chemical compounds

• Galactose transport in proteoliposomes is not significantly inhibited by the uncoupler carbonylcyanide m-chlorophenylhydrazone, but is inhibited by 0.5 mM vanadate [8].

References