期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1980
卷号:77
期号:7
页码:4007-4010
DOI:10.1073/pnas.77.7.4007
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We have tested the performance in vitro of Escherichia coli ribosomes containing or lacking the protein L7/L12. When the experiments are performed in an optimized mixture of ions (polymix), L7/L12 is required for maximal rate of synthesis as well as for minimal missense error frequency. The results in conventional Tris/Mg2+/NH4Cl buffers are different; in these buffers, only the rate of synthesis is strongly dependent on the presence of L7/L12. In addition, we show that there is a large difference between the optimal Mg2+ concentration required for speed of translation and that for accuracy of translation in conventional buffer. These optima are very close in polymix. Finally, we show that the contribution of L7/L12 to the speed of translation is obscured in translation systems that are limited by substrates. We conclude that it is not possible to analyze details of the mechanism of translation in conventional buffers.