The dilemma of phage taxonomy illustrated by comparative genomics of Sfi21-like Siphoviridae in lactic acid bacteria.

ABSTRACT: The complete genome sequences of two dairy phages, Streptococcus thermophilus phage 7201 and Lactobacillus casei phage A2, are reported. Comparative genomics reveals that both phages are members of the recently proposed Sfi21-like genus of Siphoviridae, a widely distributed phage type in low-GC-content gram-positive bacteria. Graded relatedness, the hallmark of evolving biological systems, was observed when different Sfi21-like phages were compared. Across the structural module, the graded relatedness was represented by a high level of DNA sequence similarity or protein sequence similarity, or a shared gene map in the absence of sequence relatedness. This varying range of relatedness was found within Sfi21-like phages from a single species as demonstrated by the different prophages harbore

SUBMITTER: Proux C 

PROVIDER: S-EPMC135392 | biostudies-literature | 2002 Nov

REPOSITORIES: biostudies-literature