SOS-inducing ability of native and mutant microbial ribonucleases
SOS-inducing ability of native and mutant microbial ribonucleases
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DOI：
10.1016/0027-5107(96)00012-7
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发表时间：
1996-07-22
影响因子：
2.3
通讯作者：
Kipenskaya, LV
中科院分区：
文献类型：
--
作者：
Ilinskaya, ON;Karamova, NS;Kipenskaya, LV
本文报道了用SOS显色法对不同催化活性芽孢杆菌中不同种类的微生物核糖核酸酶进行定点诱变的遗传毒性试验结果。在浓度为0.1 ~ 1 mg/ml时，野生型芽胞杆菌二酶、藤蔓二酶和突变型赖氨酸（58）赖氨酸二酶的诱导因子均显著高于1.5（1.8 ~ 2.8）。催化活性降低的突变RNase(替换了Lys(26)Ala, Arg（61)Gln, His(101)Glu的双酶）或通过天然抑制剂barstar灭活的野生型RNase没有表现出诱导sos的效力。具有与野生型RNase相当的高催化活性的天然杆菌RNase和突变酶引起SOS反应的能力表明，遗传毒性可能是通过细胞RNA的裂解介导的。讨论了催化活性核糖核酸酶诱变的可能机制。
The results of genotoxicity testing of microbial ribonucleases from Bacillus species with different catalytic activity obtained by site-directed mutagenesis in SOS chromotest are reported. At the concentrations 0.1-1 mg/ml, the induction factor for wild-type bacillar binase, barnase and mutant Arg(58)Lys binase with 100% activity was found to be significantly higher than 1.5 (1.8-2.8). Mutant RNases having decreased catalytic activity (binases with replacements Lys(26)Ala, Arg(61)Gln, His(101)Glu) or through natural inhibitor barstar inactivated wild-type RNase exhibited no SOS-inducing potency. The ability of native bacillar RNases and mutant enzymes possessing high catalytic activity comparable with the activity of wild-type RNase to cause the SOS response indicates that genotoxicity is mediated through the probable cleavage of cellular RNA.The possible mechanisms of mutagenesis induced by catalytically active RNases are discussed.