Figure 4

Inactivated or unusual DGRs. We encountered several examples of DGRs with inactivated RTs, but intact VR/TR repeats. This includes (A) nonsense mutations as in Ruminococcus gnavus ATCC 29149, where a premature stop codon truncates the RT ORF, (B) disruption of the RT ORF by insertion elements as in Acaryochloris marina MBIC11017, or (C) frameshift mutations as in Bacteroides sp. 9_1_42FAA. (D) Some DGRs contain full-length RT ORFs, but several B-to-N mutations in their VR. VRs of the respective elements are shown on the left and depicted in yellow (A-to-B mutations: orange vertical bars; B-to-N mutations: black vertical bars). The corresponding RTs are schematically shown on the right (not to scale). The 5’ part of the RT is shown as green box, inactivated parts in gray.