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：7
页码：1659-1663
DOI：10.1073/pnas.69.7.1659
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The kinetic order of synthesis of deoxycytidylate deaminase (EC 3.5.4.12 ), deoxycytidylate hydroxymethylase (EC 2.1.2.b), dihydrofolate reductase (EC 1.5.1.3 ), 5-hydroxymethyldeoxycytidylate kinase (EC 2.7.4.4 ), and thymidylate synthetase (EC 2.1.1.b) after infection of Escherichia coli with T2r+ bacteriophage was found not to correlate with their order of synthesis in an in vitro protein-synthesizing preparation. The in vivo and in vitro synthesis of enzyme-specific messenger RNA measured in the protein-synthesizing preparation preceded each enzyme by about 1 min. Through the use of sheared DNA, it was shown that the thymidylate synthetase gene was most susceptible to a loss in template activity, which suggests that this gene is further removed from its promoter than the other genes are from theirs. With a DNA segment of 2.5 x 105 daltons, the synthesis of dihydrofolate reductase alone was obtained, but at a much reduced rate. Translation of the RNA from phage-infected cells treated with chloramphenicol yielded amounts of dihydrofolate reductase and deoxycytidylate hydroxymethylase activities similar to those obtained with RNA from untreated infected cells. These results suggest that the chloramphenicol RNA, which consists primarily of immediate-early RNA, may contain most, if not all, of the information required for the synthesis of phage dihydrofolate reductase and deoxycytidylate hydroxymethylase.
