RESUMEN
Five subcluster C1 mycobacteriophages, Blackbrain, Cactojaque, Kboogie, Trinitium, and YoungMoneyMata, were isolated from soil using the host Mycobacterium smegmatis mc2155. The genome sizes range from 154,512 to 156,223 bp. The largest genome encodes 237 predicted proteins, 34 tRNAs, and 1 transfer-messenger RNA (tmRNA).
RESUMEN
Two temperate mycobacteriophages, Dallas and Jonghyun, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc2155. Analysis of the genomes revealed that Dallas and Jonghyun belong to clusters J and G, respectively. The structures of the genomes are typical of their respective clusters.
RESUMEN
Temperate phages are common, and prophages are abundant residents of sequenced bacterial genomes. Mycobacteriophages are viruses that infect mycobacterial hosts including Mycobacterium tuberculosis and Mycobacterium smegmatis, encompass substantial genetic diversity and are commonly temperate. Characterization of ten Cluster N temperate mycobacteriophages revealed at least five distinct prophage-expressed viral defence systems that interfere with the infection of lytic and temperate phages that are either closely related (homotypic defence) or unrelated (heterotypic defence) to the prophage. Target specificity is unpredictable, ranging from a single target phage to one-third of those tested. The defence systems include a single-subunit restriction system, a heterotypic exclusion system and a predicted (p)ppGpp synthetase, which blocks lytic phage growth, promotes bacterial survival and enables efficient lysogeny. The predicted (p)ppGpp synthetase coded by the Phrann prophage defends against phage Tweety infection, but Tweety codes for a tetrapeptide repeat protein, gp54, which acts as a highly effective counter-defence system. Prophage-mediated viral defence offers an efficient mechanism for bacterial success in host-virus dynamics, and counter-defence promotes phage co-evolution.
Asunto(s)
Micobacteriófagos/fisiología , Mycobacterium smegmatis/virología , Mycobacterium tuberculosis/virología , Profagos/fisiología , ADN Viral/genética , Variación Genética , Genoma Bacteriano , Genoma Viral , Ligasas/genética , Lisogenia , Micobacteriófagos/genética , Mycobacterium smegmatis/genética , Mycobacterium tuberculosis/genética , Filogenia , Profagos/enzimología , Profagos/genética , Proteínas Virales/genéticaRESUMEN
ErnieJ, a cluster C mycobacteriophage that infects Mycobacterium smegmatis mc2155, was recovered from soil in Washington, DC. Its genome is 153,243 bp in size and encodes 227 predicted proteins, 30 tRNAs, and one transfer-messenger RNA (tmRNA). Ten percent of the predicted proteins have homologs in phages that infect nonmycobacterial Actinobacteria.