9.A.12 The Putative MlbJ/Q Lantibiotic NAI-107 Immunity Protein (MLIP) Family
The actinomycete, Microbispora ATCC PTA-5024, produces the lantibiotic NAI-107, which interferes with peptidoglycan biosynthesis by binding bactoprenol-pyrophosphate-coupled peptidoglycan precursors. The immunity proteins are encoed in the NAI-107 biosynthetic gene cluster (mlb). Distinct immunity determinants are: the ABC transporter MlbYZ, and acting cooperatively, the transmembrane protein, MlbJ, and the lipoprotein, MlbQ. NMR structural analysis of MlbQ revealed a hydrophobic surface patch which is proposed to bind the cognate lantibiotic. Thus, immunity in Microbispora is not based on just one determinant but on the action of distinct immunity proteins, MlbQ, MlbYZ and MlbJ (Pozzi et al. 2015).