Functional genomic analysis of two Staphylococcus aureus phages isolated from the dairy environment
García, Pilar × Martínez, Beatriz Obeso, José María Lavigne, Rob Lurz, Rudi Rodríguez, Ana #
American Society for Microbiology (ASM)
Applied and Environmental Microbiology vol:75 issue:24 pages:7663-7673
The genomes of the two lytic mutants Staphylococcus aureus bacteriophages, vB_SauS-phiIPLA35 and vB_SauS-phiIPLA88, isolated from milk have been analyzed. Their genomes are 45,344 bp and 42,526 bp long, respectively, and contain 62 and 61 orfs. Enzymatic analyses, and sequencing revealed that the phiIPLA35 DNA molecule has 3'-protruding cohesive ends (cos) 10 bp-long, whereas phiIPLA88 DNA is 4.5% terminally redundant and most likely is packaged by a headful mechanism. N-terminal amino acid sequencing, mass spectrometry, bioinformatic analyses and functional analyses enabled the assignment of putative functions to 58 gene products, including DNA packaging proteins, morphogenetic proteins, lysis components, and proteins necessary for DNA recombination, modification and replication. Point mutations in their lysogeny control-associated genes explain their strictly lytic behaviour. Muralytic activity associated with other structural components has been detected in virions of both phages. Comparative analysis of phiIPLA35 and phiIPLA88 genome structure resembles those of varphi12 and varphi11, respectively, both representatives of large genomic groupings within the S. aureus infecting phages.