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).
References:
Putative lantibiotic (NAI-107) immunity exporter, MlbJ (247 aas; 6 TMSs)/Q (lipoprotein of 141 aas). 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 was proposed to bind the cognate lantibiotic (Pozzi et al. 2015).
Actinobacteria
MlbJQ of Microbispora sp. ATCC PTA-5024
MlbJ (membrane protein of 6 TMSs)
MlbQ (lipoprotein of 141 aas and 1 TMS)
Uncharacterized protein of 209 aas and 6 TMSs
Actinobacteria
UP of Nocardia brasiliensis
Uncharacterized pair of homologous proteins of 233 and 251 aas, encoded by adjacent genes, both with 6 TMSs. Adjacent to these two genes are an apparent ABC transporter with TC# 3.A.1.148.4. This family may also be an ABC exporter, but the ATPase is not encided by an adjacent gene and has not been identified.
Actinobacteria
UPs of Streptosporangium roseum
Uncharacterized protein of 274 aas and 6 TMSs in a 2 + 2 + 2 TMS arrangement.
UP of Nocardia amikacinitolerans