RESUMEN
General knowledge on the diversity and biology of microbial viruses infecting bacterial hosts from extreme acidic environments lags behind most other econiches. In this study, we analyse the AcaML1 virus occurrence in the taxon, its genetic composition and infective behaviour under standard acidic and SOS-inducing conditions to assess its integrity and functionality. Occurrence analysis in sequenced acidithiobacilli showed that AcaML1-like proviruses are confined to the mesothermophiles Acidithiobacillus caldus and Thermithiobacillus tepidarius. Among A. caldus strains and isolates this provirus had a modest prevalence (30%). Comparative genomic analysis revealed a significant conservation with the T. tepidarius AcaML1-like provirus, excepting the tail genes, and a high conservation of the virus across strains of the A. caldus species. Such conservation extends from the modules architecture to the gene level, suggesting that organization and composition of these viruses are preserved for functional reasons. Accordingly, the AcaML1 proviruses were demonstrated to excise from their host genomes under DNA-damaging conditions triggering the SOS-response and to produce DNA-containing VLPs. Despite this fact, under the conditions evaluated (acidic) the VLPs obtained from A. caldus ATCC 51756 could not produce productive infections of a candidate sensitive strain (#6) nor trigger it lysis.
Asunto(s)
Acidithiobacillus/virología , Bacteriófagos/fisiología , Provirus/fisiología , Acidithiobacillus/genética , Acidithiobacillus/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Bacteriófagos/genética , Bacteriófagos/aislamiento & purificación , Provirus/genética , Provirus/aislamiento & purificación , Proteínas Virales/genética , Proteínas Virales/metabolismo , Integración ViralRESUMEN
Development of reproducible genetic tools in the industrially important acidithiobacilli is urgently required. Inducible temperate phages which may be modified in vitro, propagated in suitable hosts, and used to transduce relevant genetic information to other strains and/or species are potentially valuable tools in this field of research. In order to address these current limitations, the genome sequence of an inducible temperate Myoviridae-like bacteriophage from the Acidithiobacillus caldus type strain was annotated and analyzed bioinformatically. Here, we announce the genome sequence of AcaML1 and report major findings from its annotation.