Mersacidin is a cytolysin, a lantibiotic produced by Gram-positive bacteria, The cytolysin is a 'pseudohaemolysin' which produces haemolysis on blood agar plates, but not in broth culture. Mersacidin is one of the type B lantibiotics (lanthionine-containing antibiotics) that contain post-translationally modified amino acids and cyclic ring structures. Mersacidin attacks the cell wall precursor lipid II, thereby inhibiting cell-wall synthesis.
Jiyao W et al.(2023). "The conserved domain database in 2023.",