Suppr超能文献

通过来自大肠杆菌的一种DNA糖基化酶从受损DNA中释放出咪唑环已打开的7-甲基鸟嘌呤残基。

Release of 7-methylguanine residues whose imidazole rings have been opened from damaged DNA by a DNA glycosylase from Escherichia coli.

作者信息

Chetsanga C J, Lindahl T

出版信息

Nucleic Acids Res. 1979 Aug 10;6(11):3673-84. doi: 10.1093/nar/6.11.3673.

Abstract

Double-stranded DNA containing 7-methylguanine residues whose imidazole rings have been opened, i.e. 2,6-diamino-4-hydroxy-5-N-methylformamido-pyrimidine residues, may be prepared by treatment of DNA with dimethyl sulfate followed by prolonged incubation at pH 11.4. These substituted formamidopyrimidine residues are actively removed from DNA by a DNA glycosylase present in E. coli cell extracts. The enz;me shows no apparent cofactor requirement and has a molecular weight of about 30 000. The release of ring-opened 7-methyl-guanine residues is due to a previously unrecognized activity, different from the three known E. coli DNA glycosylases that release uracil, 3-methyladenine, and hypoxanthine from DNA. This enzyme may serve to repair a major secondary alkylation product in DNA. In addition, it may remove nonmethylated purines, whose imidazole rings have been opened, from X-irradiated DNA.

摘要

含有咪唑环已打开的7-甲基鸟嘌呤残基(即2,6-二氨基-4-羟基-5-N-甲基甲酰胺基嘧啶残基)的双链DNA,可以通过用硫酸二甲酯处理DNA,然后在pH 11.4下长时间孵育来制备。这些取代的甲酰胺基嘧啶残基可被大肠杆菌细胞提取物中存在的一种DNA糖基化酶从DNA中有效去除。该酶没有明显的辅因子需求,分子量约为30000。开环的7-甲基鸟嘌呤残基的释放是由于一种以前未被认识的活性,不同于三种已知的从DNA中释放尿嘧啶、3-甲基腺嘌呤和次黄嘌呤的大肠杆菌DNA糖基化酶。这种酶可能用于修复DNA中的一种主要二级烷基化产物。此外,它可能从X射线照射的DNA中去除咪唑环已打开的非甲基化嘌呤。

相似文献

引用本文的文献

1
Bracken Fern Carcinogen, Ptaquiloside, Forms a Guanine -Adduct in DNA.蕨菜致癌物原蕨苷在DNA中形成鸟嘌呤加合物。
J Agric Food Chem. 2025 Jan 15;73(2):1053-1061. doi: 10.1021/acs.jafc.4c07187. Epub 2025 Jan 7.
7
Oxidative DNA damage & repair: An introduction.氧化DNA损伤与修复:简介
Free Radic Biol Med. 2017 Jun;107:2-12. doi: 10.1016/j.freeradbiomed.2017.03.030. Epub 2017 Mar 28.
9
Chemical Biology of N-Substituted Formamidopyrimidine DNA Adducts.N-取代甲酰胺嘧啶DNA加合物的化学生物学
Chem Res Toxicol. 2017 Jan 17;30(1):434-452. doi: 10.1021/acs.chemrestox.6b00392. Epub 2016 Dec 13.
10
Formation and processing of DNA damage substrates for the hNEIL enzymes.人NEIL酶的DNA损伤底物的形成与加工
Free Radic Biol Med. 2017 Jun;107:35-52. doi: 10.1016/j.freeradbiomed.2016.11.030. Epub 2016 Nov 20.

本文引用的文献

6
The decomposition of adenine by ionizing radiation.
Radiat Res. 1971 Jun;46(3):444-56.

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验