Identification of the receptor-binding protein in 936-species lactococcal bacteriophages

Studies done to identify genes responsible for host recognition in the lactococcal phages sk1 and bIL170 belonging to species 936 are reported. The results of the studies strongly suggest that homologous genes, orf18 in phage sk1 and orf20 in phage bIL170 encode receptor-binding protein (RBPs). Moreover, two groups of lytic lactococcal phages pertaining to species 936 were identified based on host specificity, host binding ability, and the amino acid sequence of the RBP.