(A) FCE exhibits higher specific activity than VCE. RNA capping reactions were performed using decreasing concentrations of two separate preparations of both FCE and VCE under standard conditions at 37°C for 30 min. FCE achieved 50% capping at ∼1 nM enzyme concentration, while VCE achieved the same level of capping at ∼2.5 nM enzyme concentration. (B) FCE and VCE do not discriminate between RNA initiating with guanosine or adenosine. RNA capping reactions were performed on 5′ triphosphate RNA oligonucleotides initiating with a guanosine (+1G) or an adenosine (+1A) under standard conditions at 37°C for 30 min. FCE and VCE exhibited similar level of capping activity on both +1G and +1A RNA. Data points are the average value of triplicated experiments. Error bars represent standard deviations.
