DNA CYTOSINE METHYLATION AND HEAT-INDUCED DEAMINATION
DNA CYTOSINE METHYLATION AND HEAT-INDUCED DEAMINATION
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DOI：
10.1007/bf01116426
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发表时间：
1986-04-01
影响因子：
4
通讯作者：
GEHRKE, CW
中科院分区：
文献类型：
--
作者：
EHRLICH, M;NORRIS, KF;GEHRKE, CW
研究了热诱导单链DNA中5-甲基胞嘧啶(M5C)残基转化为胸腺嘧啶核苷残基和胞嘧啶残基转化为尿嘧啶残基。在37度时计算的脱氨率。C和pH 7.4分别为.apprx。9.5次。10-10和2.1倍。10-10秒-1。N4-甲基脱氧胞苷存在于某些嗜热菌的DNA中，其耐热性比脱氧胞苷更强，比5-甲基脱氧胞苷更耐热。因此，在基因组中含有N4-甲基胞嘧啶而不是M5C的嗜热菌可以在很大程度上避免因脱氨而导致的热诱导突变，而脱氨基是许多在DNA中含有M5C的生物所引起的。
The heat-induced conversion of 5-methylcytosine (m5C) residues to thymidine residues and of cytosine to uracil residues in single-stranded DNA was studied. The calculated rates for deamination at 37.degree. C and pH 7.4 were .apprx. 9.5 .times. 10-10 and 2.1 .times. 10-10 sec-1, respectively. N4-Methyldeoxycytidine, which is in the DNA of certain thermophilic bacteria, was more heat-resistant than was deoxycytidine and much more than was 5-methyldeoxycytidine. Thermophilic bacteria which contain N4-methylcytosine rather than m5C in their genomes may thereby largely avoid heat-induced mutation due to deamination, which is incurred by the many organisms that contain m5C in their DNA.