Abstract
The genome of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronavirus has a capping modification at the 5'-untranslated region (UTR) to prevent its degradation by host nucleases. These modifications are performed by the Nsp10/14 and Nsp10/16 heterodimers using S-adenosylmethionine as the methyl donor. Nsp10/16 heterodimer is responsible for the methylation at the ribose 2'-O position of the first nucleotide. To investigate the conformational changes of the complex during 2'-O methyltransferase activity, we used a fixed-target serial synchrotron crystallography method at room temperature. We determined crystal structures of Nsp10/16 with substrates and products that revealed the states before and after methylation, occurring within the crystals during the experiments. Here we report the crystal structure of Nsp10/16 in complex with Cap-1 analog (m7GpppAm2'-O). Inhibition of Nsp16 activity may reduce viral proliferation, making this protein an attractive drug target.
Keywords:
CAP-1; Nsp10/16; SARS-CoV-2; mRNA; serial crystallography.
Copyright © 2021 the Author(s). Published by PNAS.
Publication types
-
Research Support, N.I.H., Extramural
-
Research Support, Non-U.S. Gov't
-
Research Support, U.S. Gov't, Non-P.H.S.
MeSH terms
-
Crystallography
-
Methylation
-
Methyltransferases / chemistry
-
Methyltransferases / metabolism
-
Multiprotein Complexes / chemistry
-
Multiprotein Complexes / metabolism
-
RNA Cap Analogs / chemistry
-
RNA Cap Analogs / metabolism
-
RNA Caps / chemistry
-
RNA Caps / metabolism*
-
RNA, Messenger / chemistry
-
RNA, Messenger / metabolism*
-
RNA, Viral / chemistry
-
RNA, Viral / metabolism*
-
S-Adenosylhomocysteine / chemistry
-
S-Adenosylhomocysteine / metabolism
-
S-Adenosylmethionine / chemistry
-
S-Adenosylmethionine / metabolism
-
SARS-CoV-2 / chemistry*
-
SARS-CoV-2 / genetics
-
SARS-CoV-2 / metabolism
-
Synchrotrons
-
Viral Nonstructural Proteins / chemistry
-
Viral Nonstructural Proteins / metabolism
-
Viral Regulatory and Accessory Proteins / chemistry
-
Viral Regulatory and Accessory Proteins / metabolism
Substances
-
Multiprotein Complexes
-
NSP10 protein, SARS-CoV-2
-
NSP16 protein, SARS-CoV-2
-
RNA Cap Analogs
-
RNA Caps
-
RNA, Messenger
-
RNA, Viral
-
Viral Nonstructural Proteins
-
Viral Regulatory and Accessory Proteins
-
S-Adenosylmethionine
-
S-Adenosylhomocysteine
-
Methyltransferases
-
cap I RNA (nucleoside-2'-)methyltransferase