Fig. 1.

Purification and EM characterization of a functional MACV L protein. (A) Schematic of replicon-based MACV RNA synthesis as described in text. (B) Epifluorescence miscroscopy images of cells expressing pMCm replicon in the presence of L (pL) or a catalytically inactivated mutant (pL-SDD). (Scale bars: 50 μm.) (C) Baculovirus-expressed purified MACV L (2 μg) analyzed by SDS/PAGE with Coomassie blue staining. (D) MACV in vitro RNA synthesis. Purified L (wt) or a catalytically inactivated mutant (SDD) was incubated with the corresponding reaction components in the presence of [α-³²P]GTP. Resulting RNA products were separated by denaturing gel electrophoresis. (E) Class averages of purified L in negative stain, each containing ≈100 particles. The side length of the individual images is 36 nm and the schematic displays approximate dimensions.