标题：Reconstruction of bacteriophage T4 DNA replication apparatus from purified components: rolling circle replication following de novo chain initiation on a single-stranded circular DNA template
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：1975
卷号：72
期号：12
页码：4800-4804
DOI：10.1073/pnas.72.12.4800
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The protein products of T4 bacteriophage genes 41, 43, 45, 44, and 62 have been purified to near homogeneity using an assay which measures their stimulation of DNA synthesis in a crude lysate of Escherichia coli cells in fected by an appropriate mutant phage. When all of these proteins and T4 gene 32 protein are incubated in the presence of deoxyribonucleoside and ribonucleoside triphosphates, extensive DNA synthesis occurs on both single and double-stranded DNA templates. Analysis of this in vitro system reveals most of the features attributed to in vivo DNA replication: (1) De novo DNA chain initiation is found on a single-stranded DNA template only if ribonucleoside triphosphates are present (as expected for RNA priming of Okazaki pieces on the "lagging" strand of a replication fork). (2) With single-stranded circular DNA as template, synthesis continues for many doublings. The products after extensive synthesis resemble a rolling circle as visualized in the electron microscope, with discontinuous "lagging" strand synthesis generating a long, unbranched double-stranded tail. The fact that all six mutationally identified T4 replication gene products are required for these syntheses suggests the existence of a large multienzyme complex, constituting the T4 replication apparatus.
