Autoradiograph of SDS-PAGE gel showing the formation of α-32P labeled m7GMP-nsP1 covalent complex. The reaction mixture included the standard components as described in Materials and Methods with 5 µCi of [α-32P] GTP, and ~25 pmol/100 pmol of nsP1. Incubation was at 30 °C for 30 min. A. Arrows indicate position of prestained molecular weight markers; Lane 1, 25 pmol nsP1; 2, 100 pmol of nsP1; 3, no protein; 4, no AdoMet; 5, Positive control vaccinia virus capping enzyme.