Identification and characterization of phage-resistance genes in temperate lactococcal bacteriophages
Article first published online: 4 MAR 2002
Volume 43, Issue 2, pages 509–520, January 2002
How to Cite
McGrath, S., Fitzgerald, G. F. and Sinderen, D. v. (2002), Identification and characterization of phage-resistance genes in temperate lactococcal bacteriophages. Molecular Microbiology, 43: 509–520. doi: 10.1046/j.1365-2958.2002.02763.x
- Issue published online: 4 MAR 2002
- Article first published online: 4 MAR 2002
The sie2009 gene, which is situated between the genes encoding the repressor and integrase, on the lysogeny module of the temperate lactococcal bacteriophage Tuc2009, was shown to mediate a phage-resistance phenotype in Lactococcus lactis against a number of bacteriophages. The Sie2009 protein is associated with the cell membrane and its expression leaves phage adsorption, transfection and plasmid transformation unaffected, but interferes with plasmid transduction, as well as phage replication. These observations indicate that this resistance is as a result of DNA injection blocking, thus representing a novel superinfection exclusion system. A polymerase chain reaction (PCR)-based strategy was used to screen a number of lactococcal strains for the presence of other prophage-encoded phage-resistance systems. This screening resulted in the identification of two such systems, without homology to sie2009, which were shown to mediate a phage-resistance phenotype similar to that conferred by sie2009. To our knowledge, this is the first description of a phage-encoded superinfection exclusion/injection blocking mechanism in the genus Lactococcus.