The ribosome cycle in mammalian protein synthesis. 3. Evidence that the nonribosomal proteins bound to the native smaller subunit are initiation factors.

Adenine/metabolism Animals Carbon Isotopes Carcinoma, Ehrlich Tumor/metabolism Cell Line Cell-Free System Centrifugation, Density Gradient Culture Media Cytoplasm/metabolism Formates/metabolism Models, Biological Neoplasm Proteins/biosynthesis,metabolism Peptide Chain Initiation, Translational Peptide Chain Termination, Translational Peptide Initiation Factors Poly U/pharmacology Potassium Chloride/pharmacology Protein Binding RNA, Neoplasm/biosynthesis RNA, Transfer/metabolism Ribosomes/drug effects,metabolism Tritium

Carbon Isotopes Culture Media Formates Neoplasm Proteins Peptide Initiation Factors RNA, Neoplasm Tritium Poly U Potassium Chloride RNA, Transfer Adenine