The first (6-4) photolyase with DNA damage repair activity from the Antarctic microalga Chlamydomonas sp ICE-L
The first (6-4) photolyase with DNA damage repair activity from the Antarctic microalga Chlamydomonas sp ICE-L
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来自南极微藻衣藻 ICE-L 的第一个 (6-4) 具有 DNA 损伤修复活性的光裂合酶
DOI：
10.1016/j.mrfmmm.2018.03.004
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发表时间：
2018-05-01
影响因子：
2.3
通讯作者：
Miao, Jinlai
中科院分区：
文献类型：
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作者：
An, Meiling;Zheng, Zhou;Miao, Jinlai
从南极浮冰中分离出的嗜冷微生物Chlamydiumsp. ICE-L，是地球上紫外线暴露最严重的生态系统之一，具有高效的DNA光修复能力。在此，我们首次从C. sp. ICE-L。6-4CiPhr编码559个氨基酸的多肽，pI为8.86，预测分子量为64.2 kDa。进行实时PCR以研究6-4CiPhr对UVB暴露的响应。6-4CiPhr的转录在6 h内持续上调，在6 h达到最大值62.7倍。在光解酶缺陷型大肠杆菌中表达6-4CiPhr提高了菌株的存活率。纯化蛋白的体外活性测定表明，6-4CiPhr是一种具有6-4PP修复活性的光解酶。这些发现提高了对（6-4）光裂合酶光复活机制的理解。
The psychrophilic microalga, Chlamydomonas sp. ICE-L, isolated from floating ice in the Antarctic, one of the most highly UV exposed ecosystems on Earth, displays an efficient DNA photorepair capacity. Here, the first known (6-4) photolyase gene (6-4CiPhr) from C. sp. ICE-L was identified. The 6-4CiPhr encoded 559-amino acid polypeptide with a pI of 8.86, and had a predicted Mw of 64.2 kDa. Real-time PCR was carried out to investigate the response of 6-4CiPhr to UVB exposure. The transcription of 6-4CiPhr was up-regulated continuously within 6 h, achieving a maximum of 62.7-fold at 6 h. Expressing 6-4CiPhr in a photolyase-deficient Escherichia coli strain improved survival rate of the strain. In vitro activity assays of purified protein demonstrated that 6-4CiPhr was a photolyase with 6-4PP repair activity. These findings improve understanding of photoreactivation mechanisms of (6-4) photolyase.