Nucleoside triphosphate + RNA(n) = diphosphate + RNA(n+1)
ATP + H(2)O = ADP + phosphate
Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
S-adenosyl-L-methionine + a 5'-(N(7)-methyl 5'-triphosphoguanosine)-(ribonucleotide)-[mRNA] = S-adenosyl-L-homocysteine + a 5'-(N(7)-methyl 5'-triphosphoguanosine)-(2'-O-methyl-ribonucleotide)-[mRNA]
TSAVLQ-|-SGFRK-NH(2) and SGVTFQ-|-GKFKK the two peptides corresponding to the two self-cleavage sites of the SARS 3C-like proteinase are the two most reactive peptide substrates. The enzyme exhibits a strong preference for substrates containing Gln at P1 position and Leu at P2 position.