Inducible Clostridium perfringens bacteriophages ?S9 and ?S63: Different genome structures and a fully functional sigK intervening element.

ABSTRACT: Two inducible temperate bacteriophages ?S9 and ?S63 from Clostridium perfringens were sequenced and analyzed. Isometric heads and long non-contractile tails classify ?S9 and ?S63 in the Siphoviridae family, and their genomes consist of 39,457 bp (?S9) and 33,609 bp (?S63) linear dsDNA, respectively. ?S63 has 3'-overlapping cohesive genome ends, whereas ?S9 is the first Clostridium phage featuring an experimentally proven terminally redundant and circularly permuted genome. A total of 50 and 43 coding sequences were predicted for ?S9 and ?S63, respectively, organized into 6 distinct lifestyle-associated modules typical for temperate Siphoviruses. Putative functions could be assigned to 26 gene products of ?S9, and to 25 of ?S63. The ?S9 attB attachment and insertion site is located in a non-coding region upstream of a putative phosphorylase gene. Interestingly, ?S63 integrates into the 3' part of sigK in C. perfringens, and represents the first functional skin-element-like phage described for this genus. With respect to possible effects of lysogeny, we did not obtain evidence that ?S9 may influence sporulation of a lysogenized host. In contrast, interruption of sigK, a sporulation associated gene in various bacteria, by the ?S63 prophage insertion is more likely to affect sporulation of its carrier.

SUBMITTER: Kim KP 

PROVIDER: S-EPMC3442830 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature