lantibiotic immunity ABC transporter NisG family permease (also called ABC-2 transporter NisG family permease) subunit, and similar proteins
This subfamily contains lantibiotic ABC transporter permease subunits NisG and NsuG, which are highly hydrophobic, integral membrane proteins, and part of the bacitracin ABC transport system that confers resistance to the Gram-positive bacteria in which this system operates, particularly to the lantibiotic nisin. Lantibiotics are small peptides, produced by Gram-positive bacteria, which are ribosomally-synthesized as pre-peptides and act by disrupting membrane integrity. Genes encoding the lantibiotic ABC transporter subunits are highly organized in operons containing all the genes required for maturation, transport, immunity, and synthesis. In Lactococcus lactis and Streptococcus uberis, the lantibiotic nisin is active against other Gram-positive bacteria via various modes of actions; however, its self-protection against the pore-forming nisin is mediated by the ABC transporter composed of NisF, NisE and NisG. In Streptococcus uberis, similar proteins provide self-protection against the pore-forming lantibiotic nisin U. This subfamily contains the NisG and NsuG permease subunits that transport nisin to the surface and expel it from the membrane.