DNA DOUBLE-STRAND BREAKAGE AND REMOVAL OF CROSS-LINKS IN DEINOCOCCUS-RADIODURANS
DNA DOUBLE-STRAND BREAKAGE AND REMOVAL OF CROSS-LINKS IN DEINOCOCCUS-RADIODURANS
复制标题
DOI：
10.1128/jb.155.3.1200-1207.1983
复制
发表时间：
1983-01-01
影响因子：
3.2
通讯作者：
TOTSUKA, K
中科院分区：
文献类型：
--
作者：
KITAYAMA, S;ASAKA, S;TOTSUKA, K
分离到对远紫外线(254 Nm)或伽玛射线中等敏感或对丝裂霉素C敏感的耐辐射耐药突变株。在4，5‘’，8-三甲基补骨脂素存在下，它们对365 nm的辐射也很敏感。通过转化实验，将它们分为7个互补类群(MTCA~mtcG)。与野生型一样，2个突变体(mtcD和mtce)在丝裂霉素C诱导的DNA双链中的链间交联链被去除，而其他突变体则缺乏这种修复。在亚致死剂量的丝裂霉素C作用后，野生型细胞在后孵育过程中观察到单链和双链的交联型DNA切割。DNA中交联链的这种去除对细胞似乎是必不可少的，因为如果它们在修复这些损伤的抑制条件下孵育后，它们的结肠形成能力显着降低。
Mitomycin C-sensitive mutants of D. radiodurans were isolated which were resistant to or only moderately sensitive to far UV (254 nm) or .gamma.-rays. They were also sensitive to irradiation at 365 nm in the presence of 4,5'',8-trimethylpsoralen. They were classified into 7 complementary groups (mtcA through mtcG) by transformation experiments. Interstrand cross-links in the DNA duplex induced by mitomycin C were removed in the cells of 2 mutants (mtcD and mtcE) as in the wild type, whereas the other mutants were deficient in this repair. After a sublethal dosage of mitomycin C, single- and double-stranded cuts of cross-linked DNA were observed in the wild-type cells during postincubation. This removal of cross-links in DNA seems to be indispensable for the cells since their colon-forming ability was markedly reduced if they were postincubated under an inhibitory condition for repair of these lesions.