The requirement for ribosomal proteins L7 and L12 in peptide-chain termination.

Proteins L7 and L12 from 50S ribosomal subunits of Escherichia coli are required for peptidechain termination. This termination process is inhibited by thiostrepton. Since both thiostrepton-treated ribosomes and those depleted of L7 and L12 have a markedly reduced ability to form release factor.

Influence of guanine nucleotides and elongation factors on interaction of release factors with the ribosome.

Release of formylmethionine from the reticulocyte ribosomal substrate, f[(3)H]Met-tRNA.ribosome, is promoted by reticulocyte release factor (RF). The initial rate of this reaction is stimulated by GTP but inhibited by GDPCP.