Effects of overexpression and antisense RNA expression of Orf17, a MutT-type enzyme
Effects of overexpression and antisense RNA expression of Orf17, a MutT-type enzyme
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DOI：
10.1248/bpb.29.1087
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发表时间：
2006-06-01
影响因子：
2
通讯作者：
Kamiya, Hiroyuki
中科院分区：
文献类型：
--
作者：
Hori, Mika;Asanuma, Taketoshi;Kamiya, Hiroyuki
大肠杆菌Orf17 （NtpA, NudB）蛋白是一种mff型酶，可在体外水解氧化的脱氧核糖核苷酸，包括8-羟基-2'-脱氧腺苷5'-三磷酸和8-羟基-2'-脱氧鸟苷5'-三磷酸。为了研究其在细菌体内的作用，我们引入了含有orf17基因正反义取向的质粒dna。当Orf17蛋白在mutT细胞中过表达时，rpoB突变频率降低。另一方面，当Orf17在野生型和orf135细胞中过表达时，没有观察到类似的效果。orf17基因反义RNA的表达没有产生明显的表型，如突变频率增加和对电离辐射的抗性。这些结果表明Orf17蛋白的作用是支持MutT功能，并协助消除8-羟基-2'-脱氧鸟苷核苷酸。
The Escherichia coli Orf17 (NtpA, NudB) protein, a Muff-type enzyme, hydrolyzes oxidized deoxyribonucleotides, including 8-hydroxy-2'-deoxyadenosine 5'-triphosphate and 8-hydroxy-2'-deoxyguanosine 5'-triphosphate, in vitro. To examine its in vivo role(s) in bacteria, plasmid DNAs containing the orf17 gene in the sense and antisense orientations were introduced. When the Orf17 protein was overexpressed in mutT cells, the rpoB mutant frequency was decreased. On the other hand, similar effects were not observed when Orf17 was overexpressed in wild type and orf135 cells. Expression of the antisense RNA of the orf17 gene did not produce an obvious phenotype, such as increased mutant frequency and resistance to ionizing radiation. These results suggest that the role of the Orf17 protein is to back up the MutT function, and to assist in the elimination of 8-hydroxy-2'-deoxyguanosine nucleotides.