3 research outputs found
Mobile Regulatory Cassettes Mediate Modular Shuffling in T4-Type Phage Genomes
Coliphage phi1, which was isolated for phage therapy in the Republic of Georgia,
is closely related to the T-like myovirus RB49. The ∼275 open reading
frames encoded by each phage have an average level of amino acid identity of
95.8%. RB49 lacks 7 phi1 genes while 10 phi1 genes are missing from RB49. Most
of these unique genes encode functions without known homologs. Many of the
insertion, deletion, and replacement events that distinguish the two phages are
in the hyperplastic regions (HPRs) of their genomes. The HPRs are rich in both
nonessential genes and small regulatory cassettes (promoterearly
stem-loops [PeSLs]) composed of strong σ70-like promoters
and stem-loop structures, which are effective transcription terminators. Modular
shuffling mediated by recombination between PeSLs has caused much of the
sequence divergence between RB49 and phi1. We show that exchanges between nearby
PeSLs can also create small circular DNAs that are apparently encapsidated by
the virus. Such PeSL “mini-circles” may be important vectors
for horizontal gene transfer
The phage therapy paradigm: prêt-à-porter or sur-mesure?
The present opinion is the result of discussions on the future of
phage therapy (personalized or large-scale uniform therapy?)
during the first International Congress on Viruses of Microbes,
held at the Institut Pasteur in Paris on June 21–25, 2010