The NSP14 plays an important role in viral replication and transcription. It consists of 2 domains possessing two different enzymatic activities: an N-terminal Proofreading exoribonuclease (ExoN) domain acting on both ssRNA and dsRNA replication in a 3' to 5' direction and a C-terminal cap (guanine-N7) methyltransferase (N7-MTase) domain. NSP14 is activated by NSP10 and associated cofactors (NSP7 and NSP8) leading to increased viral ExoN activity and proof-reading capacity. The NSP10/NSP14 complex may act as a replicative mismatch repair mechanism, therefore, lowering the sensitivity of the virus to RNA lethal mutations.

AENVTGLFKDCSKVITGLHPTQAPTHLSVDTKFKTEGLCVDIPGIPKDMTYRRLISMMGFKMNYQVNGYPNMFITREEAIRHVRAWIGFDVEGCHATREAVGTNLPLQLGFSTGVNLVAVPTGYVDTPNNTDFSRVSAKPPPGDQFKHLIPLMYKGLPWNVVRIKIVQMLSDTLKNLSDRVVFVLWAHGFELTSMKYFVKIGPERTCCLCDRRATCFSTASDTYACWHHSIGFDYVYNPFMIDVQQWGFTGNLQSNHDLYCQVHGNAHVASCDAIMTRCLAVHECFVKRVDWTIEYPIIGDELKINAACRKVQHMVVKAALLADKFPVLHDIGNPKAIKCVPQADVEWKFYDAQPCSDKAYKIEELFYSYATHSDKFTDGVCLFWNCNVDRYPANSIVCRFDTRVLSNLNLPGCDGGSLYVNKHAFHTPAFDKSAFVNLKQLPFFYYSDSPCESHGKQVVSDIDYVPLKSATCITRCNLGGAVCRHHANEYRLYLDAYNMMISAGFSLWVYKQFDTYNLWNTFTRLQ

527 aa; 150 kDa