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：1972
卷号：69
期号：5
页码：1192-1195
DOI：10.1073/pnas.69.5.1192
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：16 lac frameshift mutants induced by an acridine derivative, ICR-191D, in E. coli are leaky for {beta}-galactosidase activity. Activities of all mutants differ from each other and from the wild type in their stability to thermal denaturation. The leakiness is under ribosomal control, since it is strongly reduced by strA restrictive mutations and is restored by ram mutations that reverse restriction. Addition of streptomycin during growth has an effect similar to the presence of the ram mutation. These ribosomal alterations do not modify the thermal stability of the enzyme. It is suggested that the leakiness is due to an infrequent 2- or 4-base reading close to the frameshift mutation site. The possibility that not only the ribosome, but also the reading context in the messenger, plays a role in securing code fidelity is discussed.
