Structural basis and dynamics of Chikungunya alphavirus RNA capping by nsP1 capping pores.

ABSTRACT: Alphaviruses are emerging positive-stranded RNA viruses which replicate and transcribe their genomes in membranous organelles formed in the cell cytoplasm. The nonstructural protein 1 (nsP1) is responsible for viral RNA capping and gates the replication organelles by assembling into monotopic membrane-associated dodecameric pores. The capping pathway is unique to Alphaviruses; beginning with the N⁷ methylation of a guanosine triphosphate (GTP) molecule, followed by the covalent linkage of an m⁷GMP group to a conserved histidine in nsP1 and the transfer of this cap structure to a diphosphate RNA. Here, we provide structural snapshots of different stages of the reaction pathway showing how nsP1 pores recognize the substrates of the methyl-transfer reaction, GTP and S-ad

SUBMITTER: Jones R 

PROVIDER: S-EPMC10041110 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature