Initiator regions from the small size class of reovirus messenger RNA protected by rabbit reticulocyte ribosomes

In order to investigate the general utility of the rabbit reticulocyte cell-free translating system for isolation of ribosome-protected initiator regions of eukaryotic mRNA, we have studied ribosome protection of 32P-labeled reovirus small mRNA species. Our studies show that rabbit reticulocyte ribosomes protect initiator regions in at least two of the four reovirus small mRNA molecules. RNA sequence analysis demonstrates that 40 S subunits protect additional sequences to the 5' side of the initiator AUG triplet.