Mycobacteria excise DNA damage in 12-or 13-nucleotide-long oligomers by prokaryotic-type dual incisions and performs transcription-coupled repair
Mycobacteria excise DNA damage in 12-or 13-nucleotide-long oligomers by prokaryotic-type dual incisions and performs transcription-coupled repair
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DOI：
10.1074/jbc.ac120.016325
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发表时间：
2020-12-11
影响因子：
4.8
通讯作者：
Sancar, Aziz
中科院分区：
文献类型：
--
作者：
Selby, Christopher P.;Lindsey-Boltz, Laura A.;Sancar, Aziz
在核苷酸切除修复中，大块的DNA损伤，如紫外线诱导的环丁烷嘧啶二聚体，通过协调一致的双切口将损伤从基因组中移除，然后进行间隙填充和结扎。到目前为止，已经发现了两种双切口模式：原核型，去除11-13个核苷酸长的低聚物的损伤；真核型，去除24-32个核苷酸长的低聚物的损伤。然而，最近的一项研究报道，结核分枝杆菌的UvrC蛋白以一种类似于酵母和人类的方式去除损伤，这种方式在距离损伤侧翼的3 ‘端15 nt和5 ’端9 nt处产生的25个寡核苷酸中产生损伤。为了验证该模型，我们使用了我们实验室开发的体内切除实验和切除修复测序全基因组修复作图方法来确定耻垢分枝杆菌的修复模式和全基因组修复作图。我们发现，耻毛分枝杆菌具有大肠杆菌uvrA、uvrB和uvrC基因的同源物，通过在光产物上切割7 nt 5′和3或4 nt 3′，以与原核模式相同的方式从基因组中去除环丁烷嘧啶二聚体，并以类似于大肠杆菌的方式进行转录偶联修复。
In nucleotide excision repair, bulky DNA lesions such as UV-induced cyclobutane pyrimidine dimers are removed from the genome by concerted dual incisions bracketing the lesion, followed by gap filling and ligation. So far, two dual-incision patterns have been discovered: the prokaryotic type, which removes the damage in 11-13-nucleotide-long oligomers, and the eukaryotic type, which removes the damage in 24-32-nucleotide-long oligomers. However, a recent study reported that the UvrC protein of Mycobacterium tuberculosis removes damage in a manner analogous to yeast and humans in a 25-mer oligonucleotide arising from incisions at 15 nt from the 3 ' end and 9 nt from the 5 ' end flanking the damage. To test this model, we used the in vivo excision assay and the excision repair sequencing genome-wide repair mapping method developed in our laboratory to determine the repair pattern and genome-wide repair map of Mycobacterium smegmatis. We find that M. smegmatis, which possesses homologs of the Escherichia coli uvrA, uvrB, and uvrC genes, removes cyclobutane pyrimidine dimers from the genome in a manner identical to the prokaryotic pattern by incising 7 nt 5 ' and 3 or 4 nt 3 ' to the photoproduct, and performs transcription-coupled repair in a manner similar to E. coli.