SEQUENCE-ANALYSIS AND CHARACTERIZATION OF PHI-O1205, A TEMPERATE BACTERIOPHAGE INFECTING STREPTOCOCCUS-THERMOPHILUS CNRZ1205

The complete nucleotide sequence of phi O1205, a temperate bacteriopha ge infecting Streptococcus thermophilus strain CNRZ1205, was determine d. The phage genome has a unit length of 43075 bp and appears to be pa ckaged by the so-called headful mechanism. The genomic organization an d structure of phi O1205 resemble those of several temperate lactococc al phages that display a life-cycle-specific organization, where ORFs believed to be involved in the lysogenic life-cycle are clustered and arranged in an orientation opposite to the ORFs supposedly involved in the lytic life-cycle. Database searches revealed putative functions f or several identified ORFs and further indicated that phi O1205 is gen etically related to a particular group of lactococcal phages. Three ge nes encoding the major structural proteins were identified on the phi O1205 genome. The phage attachment site attP, the bacterial attachment site attB, and the two phage/chromosome junctions attL and attR were identified and found to contain a 40 bp common core sequence.