Open AccessRole of Ribosomal Protein S1 in Protein Synthesis: Effects of Its Addition to Bacillus stearothermophilus Cell‐Free System
Author(s) -
ISONO Setsuko,
ISONO Katsumi
Publication year - 1975
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1975.tb02202.x
Subject(s) - ribosome , ribosomal rna , escherichia coli , ribosomal protein , protein biosynthesis , biology , cell free system , 50s , biochemistry , microbiology and biotechnology , rna , in vitro , gene
Products of the f2 phage RNA‐directed protein synthesizing systems in vitro , derived from Escherichia coli and Bacillus stearothermophilus , were analyzed. In contrast to other reports, it was found that B. stearothermophilus ribosomes synthesized phage coat protein when the high‐speed (1 x g ) supernatant (S 100 ) and ribosomal wash (crude initiation factors) of homologous origin were used. Furthermore, a marked stimulation of coat protein synthesis was observed with B. stearothermophilus ribosomes when either S 100 or ribosomal wash or both from E. coli cells were used instead of the respective homologous components. The principle responsible for this stimulation was identified as the 30‐S ribosomal protein S1 present in S 100 and ribosomal wash. Purified S1 from E. coli at roughly one‐to‐one molar ratio to ribosomes resulted in about 10‐fold stimulation of the incorporation of [ 14 C]valine when added to the B. stearothermophilus system. This stimulation was observed mainly in the synthesis of coat protein and replicase.