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双链断裂修复中的II组内类反转录酶功能
Seung Kuk Park1, Georg Mohr1, Jun Yao1
1Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA.
Cell
|September 16, 2022
概括
细菌具有用于DNA修复的逆转录酶 (RT). 这些酶通过微同质介导端结合 (MMEJ) 进行转化DNA合成和双链断裂修复 (DSBR).
科学领域:
- 分子生物学
- 遗传学
- 生物化学
背景情况:
- 细菌编码逆转录酶 (RTs),其结构与II组内核RTs有关,其功能基本未知.
- 已知II组内RT是参与RNA拼接和回归归的移动遗传元素.
研究的目的:
- 研究Pseudomonas aeruginosa的II组内体类RT (G2L4RT) 的功能.
- 确定细菌RT能否在DNA修复途径中发挥作用,特别是转化DNA合成和双链断裂修复 (DSBR).
主要方法:
- G2L4 RT的生化特征
- 在大肠杆菌中表达G2L4RT.
- 位点定向的突变生成以分析活性位点残留物 (YIDD与YADD).
- 与人类DNA修复聚合酶和其他非LTR反元素RT进行比较分析.
主要成果:
- 具有YIDD活性位点的G2L4 RT在本地宿主和大肠杆菌中表现出DNA修复活动.
- G2L4 RT通过微同质介导端结合 (MMEJ) 进行转化DNA合成和DSBR.
- 它的生物化学活动与人类DNA修复聚合酶甲相似.
- 在II组内RT和G2L4RT中,相互的活性部位替代显示出异黄素有利于MMEJ,而氨酸有利于原料延伸.
结论:
- 细菌II组内体类RT具有固有的DNA修复能力,包括DSBR.
- 这些功能依赖于与真核生物非LTR反元素RT共享的保存结构特征.
- 细菌RT可能在多种生物体中起着保留作用.
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