The effect of Escherichia coli ribosomal protein S1 on the translational specificity of bacterial ribosomes.
Ribosomes from Gram-negative bacteria such as Escherichia coli exhibit non-specific translation of bacterial mRNAs. That is, they are able to translate mRNAs from a variety of sources in a manner independent of the "strength" of the Shine-Dalgarno region, in contrast to ribosomes from many Gram-positive bacteria, such as Bacillus subtilis, which show specific translation in only being able to translate other Gram-positive mRNA, or mRNAs that have "strong" Shine-Dalgarno regions. There is an evolutionary correlation between the translational specificity and the absence of a protein analogous to E. coli ribosomal protein S1. The specificity observed with B. subtilis ribosomes is a function of their 30 S subunit which lacks S1; translation of Gram-negative mRNA can occur with heterologous ribosomes containing the 30 S subunit of E. coli ribosomes and the 50 S subunit of B. subtilis ribosomes. However, the addition of E. coli S1 alone to B. subtilis ribosome does not overcome their characteristic inability to translate mRNA from Gram-negative organisms. By contrast, the removal of S1 from E. coli ribosomes results in translational behavior similar to that shown by B. subtilis ribosomes in that the S1-depleted E. coli ribosomes can translate mRNA from Gram-positive sources in the absence of added S1, although addition of S1 stimulates further translation of such mRNAs by the E. coli ribosomes.
Roberts
M W
MW
Department of Biochemistry, University of California, Berkeley 94720.
Rabinowitz
J C
JC
D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D010802:Phylogeny; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D012269:Ribosomal Proteins / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D013045:Species Specificity
D012333:RNA, Messenger; D012269:Ribosomal Proteins; C015494:ribosomal protein S1