7-Deazaguanine modifications protect phage DNA from host restriction systems.

ABSTRACT: Genome modifications are central components of the continuous arms race between viruses and their hosts. The archaeosine base (G⁺), which was thought to be found only in archaeal tRNAs, was recently detected in genomic DNA of Enterobacteria phage 9g and was proposed to protect phage DNA from a wide variety of restriction enzymes. In this study, we identify three additional 2'-deoxy-7-deazaguanine modifications, which are all intermediates of the same pathway, in viruses: 2'-deoxy-7-amido-7-deazaguanine (dADG), 2'-deoxy-7-cyano-7-deazaguanine (dPreQ₀) and 2'-deoxy-7- aminomethyl-7-deazaguanine (dPreQ₁). We identify 180 phages or archaeal viruses that encode at least one of the enzymes of this pathway with an overrepresentation (60%) of viruses potentially in

SUBMITTER: Hutinet G 

PROVIDER: S-EPMC6884629 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature