Table 2.

Mismatch base pairs created by the RdRp.

RNTP omitted during elongation
Elongation RNTP mix	no rCTP	no rATP	no rGTP	no rUTP
RNA template: COV-RNA1	At template G	At template U	At template C	At template A
Full-length product?	No	Yes	Yes	Yes
Possible base pairs	Stalls at template G	U:C, U:G, U:U	[C:C], C:U,[C:A]	[A:A], A:C, [A:G]
RNA template encodes for only one nucleotide
Elongation RNTP mix	rGTP, rUTP, rATP, or rCTP	rGTP, rUTP, rATP, or rCTP	rGTP, rUTP, rATP, or rCTP	rGTP, rUTP, rATP, or rCTP
RNA template	CoV-RNA1-G	CoV-RNA1-U	CoV-RNA1-C	CoV-RNA1-A
Full-length product?	No full length	Yes	Yes	Yes
Observed base pairs	No full length	U:C, U:G, U:U, U:A	C:G, C:U	A:U, A:C

Bold bracket base pairs indicate mismatches that do not occur, and italic font indicates mismatches generated by the RdRp.

Possible and observed base pairs are written in the 5′–3′ direction, with the template nucleotide underlined.