Comparative genomics of Cluster O mycobacteriophages
- Steven G. Cresawny(Author),
- Welkin H. Popeo(Author),
- Deborah Jacobs-Serao(Author),
- Charles A. Bowmano(Author),
- Daniel A. Russello(Author),
- Rebekah M. Dedricko(Author)
- ,
- bCarthage College,
- cUniversity of Maine,
- dBaylor University,
- eSeton Hill University,
- fProvidence College
Open access
Abstract
Mycobacteriophages - viruses of mycobacterial hosts - are genetically diverse but morphologically are all classified in the Caudovirales with double-stranded DNA and tails. We describe here a group of five closely related mycobacteriophages - Corndog, Catdawg, Dylan, Firecracker, and YungJamal - designated as Cluster O with long flexible tails but with unusual prolate capsids. Proteomic analysis of phage Corndog particles, Catdawg particles, and Corndog-infected cells confirms expression of half of the predicted gene products and indicates a non-canonical mechanism for translation of the Corndog tape measure protein. Bioinformatic analysis identifies 8-9 strongly predicted SigA promoters and all five Cluster O genomes contain more than 30 copies of a 17 bp repeat sequence with dyad symmetry located throughout the genomes. Comparison of the Cluster O phages provides insights into phage genome evolution including the processes of gene flux by horizontal genetic exchange.