RNA-protein complexes responsible for replication and transcription of the double-stranded RNA bacteriophage phi 6.

RNA-protein complexes active for transcription and replication of the double-stranded RNA bacteriophage phi 6 have been partially purified from lysates of infected Pseudomonas phaseolicola. Transcribing particles (filled procapsids) contain the three viral dsRNAs and all four procapsid proteins P1, P2, P4, and P7. Particles with replicase activity contain the same four proteins as well as single plus RNA strands duplexed with various extents of minus strands initiated in vivo. The in vitro replication reaction is insensitive to RNaseA. Sarkosyl destroys transcription complexes but does not reduce the activity of replication complexes, although the latter lose 80% of their P4 and the single-strand RNA template becomes sensitive to RNase. The detection of complexes that replicate small only, or both small and medium, RNA suggests that the RNAs are packaged sequentially in the order small, medium, large.