title: Protein synthesis defects in temperature-sensitive mutants of Escherichia coli with altered ribosomal proteins.
abstract: The ribosomes from four temperature-sensitive mutants of Escherichia coli have been examined for defects in cell-free protein synthesis. The mutants examined had alterations in ribosomal proteins S10, S15, or L22 (two strains). Ribosomes from each mutant showed a reduced activity in the translation of phage MS2 RNA at 44 degrees C and were more rapidly inactivated by heating at this temperature compared to control ribosomes. Ribosomal subunits from three of the mutants demonstrated a partial or complete inability to reassociate at 44 degrees C. 70-S ribosomes from two strains showed a reducton in messenger RNA binding. tRNA binding to the 30 S subunit was reduced in the strains with altered 30-S proteins and binding to the 50 S subunit was affected in the mutants with a change in 50 S protein L22. The relation between ribosomal protein structure and function in protein synthesis in these mutants is discussed.
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D014176:Protein Biosynthesis; D011487:Protein Conformation; D012329:RNA, Bacterial / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics* / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012269:Ribosomal Proteins