Molecular basis of specific viral RNA recognition and 5′-end capping by the Chikungunya virus nsP1

Kuo Zhang, Michelle Cheok Yien Law, Trinh Mai Nguyen, Yaw Bia Tan, Melissa Wirawan, Yee-Song Law, Lak Shin Jeong, Dahai Luo
2022 Cell Reports  
Many viruses encode RNA-modifying enzymes to edit the 5' end of viral RNA to mimic the cellular mRNA for effective protein translation, genome replication, and evasion of the host defense mechanisms. Alphavirus nsP1 synthesizes the 5' end Cap-0 structure of viral RNAs. However, the molecular basis of the capping process remains unclear. We determine high-resolution cryoelectron microscopy (cryo-EM) structures of Chikungunya virus nsP1 in complex with m7GTP/SAH, covalently attached m7GMP, and
more » ... -0 viral RNA. These structures reveal details of viral-RNA-capping reactions and uncover a sequence-specific virus RNA-recognition pattern that, in turn, regulates viral-RNA-capping efficiency to ensure optimal genome replication and subgenomic RNA transcription. This sequence-specific enzyme-RNA pairing is conserved across all alphaviruses.
doi:10.1016/j.celrep.2022.111133 pmid:35905713 fatcat:qpthgl3mgzgzlejncx26jxx2xm