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：1974
卷号：71
期号：1
页码：11-15
DOI：10.1073/pnas.71.1.11
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In a protein-synthesizing system extracted from E. coli, purified DNA from corynephages {beta}ctox+ and {beta}45c was used to direct the in vitro synthesis of diphtheria toxin and of the related nontoxic protein, CRM45, as well as of other {beta}-phage proteins. When {beta}ctox+-DNA or {beta}c-DNA was added to a similar system extracted from the nonlysogenic Corynebacterium diphtheriae strain, C7s(-)tox-, neither toxin nor the CRM45 protein was produced, although other {beta}-phage proteins were synthesized in amounts equivalent to those produced in the E. coli system from the same amount of {beta}-phage DNA. Preliminary experiments suggest that both toxinogenic and nontoxinogenic strains of the diphtheria bacillus contain a factor that specificially blocks expression of the tox gene. Synthesis of toxin and the CRM45 protein in the E. coli system could not be inhibited by relatively high concentrations of inorganic iron, but could be inhibited by extracts from the C7s(-)tox- strain of C. diphtheriae.
关键词：diphtheria toxin ; in vitro protein synthesis ; corynephage β
