Some properties of reticulocyte ribosomal subunits

Abstract

A method for preparing the subunits of reticulocyte ribosomes is described. These subunits are active for hemoglobin and polyphenylalanine synthesis. The subunits bind phenylalanyl-RNA enzymically using poly U as a messenger RNA. These three activities are a result of reassociation of the subunits into primarily monomeric ribosomes. The ability of the subunit preparation to participate in the above reactions is rapidly lost at 0 °. This loss of activity is paralleled by a loss in the ability to reassociate into monomeric ribosomes. The smaller 30S subunit can bind polyuridylic acid while nascent polyphenylalanine is bound to the 47S subunit.