nsp16 acts as a cap 2'-O-methyltransferase to modify SARS-CoV-1 gRNA complement (minus strand)

Stable Identifier
Reaction [transition]
Homo sapiens
Related Species
Human SARS coronavirus
Locations in the PathwayBrowser
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The genomic and subgenomic mRNAs of SARS-CoV-1 coronavirus, including the minus strand genomic RNA, are presumed to be capped at their 5′ end, based on studies of the mouse hepatitis virus (MHV) (Lai and Stohlman 1981) and the equine torovirus (van Vliet et al. 2002). Non-structural protein 16 (nsp16) acts as a 2'O-methyltransferase that converts coronavirus cap-0 to cap-1, which was first demonstrated with nsp16 cloned from the feline coronavirus (FCV) (Decroly et al. 2008). Cap-0 represents N7-methyl guanosine connected to the 5′ nucleotide through a 5′ to 5′ triphosphate linkage (also known as m7G cap or m7Gppp cap). Cap-1 is generated by an additional methylation on the 2′O position of the initiating nucleotide, and is also known as m7GpppNm. Non-structural protein 10 (nsp10) acts as an activator of nsp16 and is necessary for cap-1 synthesis (Bouvet et al. 2010, Decroly et al. 2011). Coronavirus RNAs with cap-1 are protected from IFIT-mediated interferon response. IFITs are interferon-induced proteins with tetratricopeptide repeats that recognize unmethylated 2'-O RNAs and act to inhibit expression of virally encoded mRNAs (Menachery et al. 2014).

Literature References
PubMed ID Title Journal Year
21637813 Crystal structure and functional analysis of the SARS-coronavirus RNA cap 2'-O-methyltransferase nsp10/nsp16 complex

Bricogne, G, Ferron, F, Canard, B, Ortiz-Lombardia, M, Gluais, L, Papageorgiou, N, Sharff, A, Lescar, J, Coutard, B, Decroly, E, Imbert, I, Bouvet, M, Debarnot, C

PLoS Pathog. 2011
20421945 In vitro reconstitution of SARS-coronavirus mRNA cap methylation

Canard, B, Selisko, B, Decroly, E, Imbert, I, Snijder, EJ, Bouvet, M, Debarnot, C

PLoS Pathog. 2010
Catalyst Activity

mRNA (nucleoside-2'-O-)-methyltransferase activity of m7GpppA-capped SARS-CoV-1 genomic RNA complement (minus strand):RTC [double membrane vesicle viral factory outer membrane]

Name Identifier Synonyms
severe acute respiratory syndrome DOID:2945 SARS-CoV infection, SARS
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