一种将天然DNA转化为约8×10⁵道尔顿片段的鼠伤寒沙门氏菌核酸内切酶。

A Salmonella typhimurium endonuclease that converts native DNA to fragments of about 8 X 10(5) daltons.

作者信息

Schumann W, Bade E G

出版信息

J Gen Microbiol. 1977 Aug;101(2):319-25. doi: 10.1099/00221287-101-2-319.

Abstract

Crude extracts of Salmonella typhimurium were found to contain an endonuclease that degraded double-stranded linear DNA from bacteria and phages to fragments with a molecular weight of about 8 X 10(5). The nuclease did not have an absolute requirement for Mg2+. One discrete intermediate product had a molecular weight of 6-6 X 10(6). Extracts from two different mutants were tested: one completely lacked the endonuclease activity (strain DB5575), and the other showed an absolute requirement for Mg2+ (strain 4543). No biological role has yet been found for this endonuclease of S. typhimurium.

摘要

鼠伤寒沙门氏菌的粗提取物被发现含有一种核酸内切酶，该酶能将细菌和噬菌体的双链线性DNA降解为分子量约为8×10⁵的片段。这种核酸内切酶对Mg²⁺没有绝对需求。一种离散的中间产物分子量为6 - 6×10⁶。测试了来自两种不同突变体的提取物：一种完全缺乏核酸内切酶活性（菌株DB5575），另一种对Mg²⁺有绝对需求（菌株4543）。尚未发现鼠伤寒沙门氏菌的这种核酸内切酶有生物学作用。