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A conserved arginine in NS5 binds genomic 3′ stem–loop RNA for primer-independent initiation of flavivirus RNA replication

Authors :
Charlotte Flory
Kitt Wing Ki Chan
Jade K. Forwood
Julien Lescar
Sai Wang
Min Jie Alvin Tan
Dahai Luo
Subhash G. Vasudevan
Lee Kong Chian School of Medicine (LKCMedicine)
School of Biological Sciences
Source :
RNA. 28:177-193
Publication Year :
2021
Publisher :
Cold Spring Harbor Laboratory, 2021.

Abstract

The commitment to replicate the RNA genome of flaviviruses without a primer involves RNA-protein interactions that have been shown to include the recognition of the stem-loop A (SLA) in the 5' untranslated region (UTR) by the nonstructural protein NS5. We show that DENV2 NS5 arginine 888, located within the carboxy-terminal 18 residues, is completely conserved in all flaviviruses and interacts specifically with the top-loop of 3'SL in the 3'UTR which contains the pentanucleotide 5'-CACAG-3' previously shown to be critical for flavivirus RNA replication. We present virological and biochemical data showing the importance of this Arg 888 in virus viability and de novo initiation of RNA polymerase activity in vitro. Based on our binding studies, we hypothesize that ternary complex formation of NS5 with 3'SL, followed by dimerization, leads to the formation of the de novo initiation complex that could be regulated by the reversible zipping and unzipping of cis-acting RNA elements. National Medical Research Council (NMRC) National Research Foundation (NRF) Published version Financial support in part from the National Research Foundation (NRF2016-CRP001-063) and National Medical Research Council of Singapore (NMRC grants MOH-000086: MOH-OFIRG18-may-0006) is gratefully acknowledged.

Details

ISSN :
14699001 and 13558382
Volume :
28
Database :
OpenAIRE
Journal :
RNA
Accession number :
edsair.doi.dedup.....bbefead6ccb94b74983fd4f6305d9ffb
Full Text :
https://doi.org/10.1261/rna.078949.121