Sequence analysis of the Lactobacillus plantarum bacteriophage PhiJL-1.

The complete genomic sequence of a Lactobacillus plantarum virulent phage PhiJL-1 was determined. The phage possesses a linear, double-stranded, DNA genome consisting of 36,677 bp with a G+C content of 39.36%. A total of 52 possible open reading frames (ORFs) were identified. According to N-terminal amino acid sequencing and bioinformatic analyses, proven or putative functions were assigned to 21 ORFs (41%), including 5 structural protein genes. The PhiJL-1 genome shows functionally related genes clustered together in a genome structure composed of modules for DNA replication, DNA packaging, head and tail morphogenesis, and lysis. This type of modular genomic organization was similar to several other phages infecting lactic acid bacteria. The structural gene maps revealed that the order of the head and tail genes is highly conserved among the genomes of several Siphoviridae phages, allowing the assignment of probable functions to certain uncharacterized ORFs from phage PhiJL-1 and other Siphoviridae phages.