7z2j

Structural highlights

Function

R1AB_WBV24 Catalyzes the RNA N7-guanylyltransferase reaction to methylate the core cap structure GpppN-RNA into the type-0 cap (m)GpppN-RNA.^[1] The 3C-like serine proteinase is responsible for the majority of cleavages.^[2] The helicase which contains a zinc finger structure displays RNA and DNA duplex-unwinding activities with 5' to 3' polarity. The exoribonuclease acts on ssRNA in a 3' to 5' direction (PubMed:30058998). Most active on dsRNA substrates containing one or two non-paired 3'-terminal nucleotides, thereby probably increasing the fidelity of the viral RNA-dependent RNA polymerase by excising RNA 3'-end mismatches during viral RNA replication (PubMed:30058998).^[3] NendoU is a Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond. Catalyzes the RNA 2'-O-ribose methyltransferase reaction to methylate the type-0 cap into the type-1 cap (m)GpppN(m)-RNA.[UniProtKB:P0C6X7]

References

1. ↑ Shannon A, Sama B, Gauffre P, Guez T, Debart F, Vasseur JJ, Decroly E, Canard B, Ferron F. A second type of N7-guanine RNA cap methyltransferase in an unusual locus of a large RNA virus genome. Nucleic Acids Res. 2022 Oct 21. pii: 6761739. doi: 10.1093/nar/gkac876. PMID:36265859 doi:http://dx.doi.org/10.1093/nar/gkac876
2. ↑ Ulferts R, Mettenleiter TC, Ziebuhr J. Characterization of Bafinivirus main protease autoprocessing activities. J Virol. 2011 Feb;85(3):1348-59. PMID:21068254 doi:10.1128/JVI.01716-10
3. ↑ Durzynska I, Sauerwald M, Karl N, Madhugiri R, Ziebuhr J. Characterization of a bafinivirus exoribonuclease activity. J Gen Virol. 2018 Sep;99(9):1253-1260. PMID:30058998 doi:10.1099/jgv.0.001120