Pol B, a Family B DNA Polymerase, in Thermococcus kodakarensis is Important for DNA Repair, but not DNA Replication
Pol B, a Family B DNA Polymerase, in Thermococcus kodakarensis is Important for DNA Repair, but not DNA Replication
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DOI：
10.1264/jsme2.me19075
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发表时间：
2019-09-25
影响因子：
2.2
通讯作者：
Higashibata, Hiroki
中科院分区：
文献类型：
--
作者：
Kushida, Takashi;Narumi, Issay;Higashibata, Hiroki
kodakarensis热球菌具有Pol B和Pol d两种DNA聚合酶，我们获得了polB完全缺失的T. kodakarensis菌株（DPB1）和polB过表达的DPB1衍生物；两种菌株均未表现出生长延迟现象，说明Pol B的缺失或过表达均不影响细胞生长。我们还发现，DPB1对四种dna损伤剂（紫外线C照射、伽马射线照射、甲磺酸甲酯和丝裂霉素C）的敏感性高于亲本菌株。通过引入含有pol B的质粒，DPB1的敏感性恢复到亲本菌株的水平，这表明DPB1的DNA损伤敏感表型是由于pol B的缺失造成的。这些结果表明，pol B参与DNA修复，但不参与DNA复制，这反过来意味着pol D是热球菌物种中唯一的复制DNA聚合酶。
Thermococcus kodakarensis possesses two DNA polymerases, Pol B and Pol D. We generated a T. kodakarensis strain (DPB1) in which polB was completely deleted and a derivative of DPB1 in which polB was overexpressed; neither of the generated strains exhibited any growth delay, indicating that the lack or overexpression of Pol B in T. kodakarensis did not affect cell growth. We also found that DPB1 showed higher sensitivity to four DNA-damaging agents (ultraviolet C irradiation, gamma-ray irradiation, methyl methanesulfonate, and mitomycin C) than the parental strain. The sensitivity of DPB1 was restored to the level of the parent strain by the introduction of a plasmid harboring pol B, suggesting that the DNA damage-sensitive phenotype of DPB1 was due to the loss of pol B. Collectively, these results indicate that Pol B is involved in DNA repair, but not DNA replication, which, in turn, implies that Pol D is the sole replicative DNA polymerase in Thermococcus species.