Yeast 20 S RNA replicon. Replication intermediates and encoded putative RNA polymerase.

摘要: Abstract The 20 S RNA genome is a circular single-stranded replicon, present in most laboratory yeast strains, whose copy number induced 10,000-fold by transfer of cells to acetate medium without carbon source. We have sequenced the genome, and (+) strand has long open reading frame with potential encode protein homology viral RNA-dependent polymerases. presence typical cAMP-dependent phosphorylation site putative polymerase suggests that amplification might be mediated cAMP, signal known transmit same nutritional status information sporulation-control system. Our inability clone across gap sequence either autocatalytic cleavage reverse transcriptase reaction, an unusual linkage 5' 3' ends fundamentally linear molecule, or structure unusually resistant transcription. identity our accompanying paper (Rodriguez-Cousino, N., Esteban, L.M., R. (1991) J. Biol. Chem. 266, 12772-12778) for W double-stranded (dsRNA) replicative form RNA. (-) strands greater than unit length molecules rolling circle mode replication as been suggested viroids.