大肠杆菌dna A基因及其整合抑制在M13噬菌体DNA合成中的作用。

The role of Escherichia coli dna A gene and its integrative suppression in M13 coliphage DNA synthesis.

作者信息

Mitra S, Stallions D R

出版信息

Eur J Biochem. 1976 Aug 1;67(1):37-45. doi: 10.1111/j.1432-1033.1976.tb10629.x.

DOI:10.1111/j.1432-1033.1976.tb10629.x

Abstract

An F+ derivative of Escherichia coli E508 thermosensitive in dna A function (involved in DNA synthesis initiation), its revertant and an Hfr derivative of E508 (ts) in which the temperature-sensitive phenotype is suppressed by integrative suppression have been compared for their ability to support M13 phage DNA synthesis at the nonpermissive temperature. Upon infection at the nonpermissive temperature, both the revertant and the Hfr strain support normal phage replication while the temperature-sensitive mutant does not. However, when infection is carried out at a permissive temperature and the temperature is shifted up after infection, phage synthesis occurs in the temperature-sensitive mutant also, but in lesser quantity than in the revertant strain. Analysis of intracellular labeled phage DNA indicates: (a) parental replicative form DNA synthesis is not dependent on dna A function; (b) progeny replicative form DNA synthesis is strongly inhibited in the temperature-sensitive dna A mutant at the nonpermissive temperature; (c) progeny single-strand DNA synthesis does not absolutely require dna A function; (d) progeny single-strand DNA is present in the circular form. The implication of the host DNA replication in M13 DNA synthesis is discussed.

摘要

大肠杆菌E508的一种F +衍生物在dna A功能（参与DNA合成起始）方面是温度敏感型的，其回复突变体以及E508（ts）的一种Hfr衍生物（其中温度敏感表型通过整合抑制得以抑制）已就它们在非允许温度下支持M13噬菌体DNA合成的能力进行了比较。在非允许温度下感染时，回复突变体和Hfr菌株均支持正常的噬菌体复制，而温度敏感突变体则不然。然而，当在允许温度下进行感染并在感染后升高温度时，温度敏感突变体中也会发生噬菌体合成，但数量比回复突变体菌株中的少。对细胞内标记的噬菌体DNA的分析表明：（a）亲本复制型DNA的合成不依赖于dna A功能；（b）在非允许温度下，温度敏感的dna A突变体中后代复制型DNA的合成受到强烈抑制；（c）后代单链DNA的合成并非绝对需要dna A功能；（d）后代单链DNA以环状形式存在。讨论了宿主DNA复制在M13 DNA合成中的意义。