Widespread distribution of a group I intron and its three deletion derivatives in the lysin gene of Streptococcus thermophilus bacteriophages.

ABSTRACT: Of 62 Streptococcus thermophilus bacteriophages isolated from various ecological settings, half contain a lysin gene interrupted by a group IA2 intron. Phage mRNA splicing was demonstrated. Five phages possess a variant form of the intron resulting from three distinct deletion events located in the intron-harbored open reading frame (orf 253). The predicted orf 253 gene sequence showed a significantly lower GC content than the surrounding intron and lysin gene sequences, and the predicted protein shared a motif with endonucleases found in phages from both gram-positive and gram-negative bacteria. A comparison of the phage lysin genes revealed a clear division between intron-containing and intron-free alleles, leading to the establishment of a 14-bp consensus sequence associated with intron

SUBMITTER: Foley S 

PROVIDER: S-EPMC111580 | biostudies-literature | 2000 Jan

REPOSITORIES: biostudies-literature