Viral RNA-dependent RNA polymerase initiates transcription/replication at a flavin adenine dinucleotide (FAD), resulting in a 5'- FAD cap on viral RNAs. In this way, recognition of viral 5' RNA by host antiviral receptors can be bypassed.
FAD nucleotidyltransferase (RNA-dependent)
RNA nucleotidyltransferase (RNA-dependent) EC 184.108.40.206 RHEA:21248
Viral RdRp are characterized by a conserved motif in which two conserved aspartic acid residues are bound to two magnesium ions. The reaction begins with the deprotonation of primer's 3' OH, in a manner that doesn't require a base . Subsequently, the 3'-oxygen acts as a nucleophile to attack the phosphate bond and eventually releases a pyrophosphate.
Hepatitis C virus RNA is 5'-capped with flavin adenine dinucleotide
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