Cell-type capping

RNAs are capped by a viral reaction similar to that in the cell. GTP is first covalently bound to GTase as GTase-GMP, which is then transferred to the processed ppRNA to form a GpppN RNA. The RNA is further N7-methylated and 2'O-methylated by two other viral enzymes.

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RNA triphosphatase: Rhea 67004
GTase-Lys-GMP reaction: (reoviridae, Poxviridae)
GTase-Arg-GMP reaction: (Flaviridae)
Guanylyl transfer on viral RNA: Rhea 67012
N7methyltransferase: Rhea 67008
2'O Mtase reaction: Rhea 67020

virusRNA TPAse
Rhea 67004
GTase
Rhea 67012
N7MTase
Rhea 67008
2'O methylase
Rhea 67020
Vaccinia (Poxvirus)D1RD1R
(GTase-Lys-GMP)
D1R +D12L J3R
Flaviviruses (Dengue virus)NS3NS5
(GTase-Arg-GMP)
NS5NS5
Orbivirus(Bluetongue virus)VP4VP4
(GTase-Lys-GMP)
VP4VP4
Mammalian orthoreovirusLambda2Lambda2
(GTase-Lys-GMP)
Lambda2Lambda2
MimivirusMimiCE MimiCE
(GTase-Lys-GMP)
MimiCE
BaculovirusLEF-4LEF-4
(GTase-Lys-GMP)
UnknownAc69
ChlorellavirusA449RA103R
(GTase-Lys-GMP)
UnknownUnknown
Mimivirus TPase
VP4 bluetongue virus TPase, GTAse, 2'O MTase