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通过Tn3溶解酶进行特定位点重组:前向和反向反应的拓变化
W M Stark1, D J Sherratt, M R Boocock
1Institute of Genetics, University of Glasgow, Scotland.
Cell
|August 25, 1989
概括
Tn3溶解酶调解特定位点的DNA重组,其链接变化为+4或-4.4. 反向反应涉及特定的DNA包裹和180度旋转机制,与lambda整合酶不同.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 特定位置的重组对于各种生物过程中的DNA操纵至关重要.
- Tn3溶解酶是催化DNA重组的关键酶,具有明显的前向和反向反应.
研究的目的:
- 阐明Tn3溶解酶催化位点特异性重组的拓机制.
- 为了研究在分辨率和连锁融合过程中的DNA包裹和链交换动态.
主要方法:
- 在前向和反向反应期间分析连接变化 (delta Lk).
- 拓学研究以确定DNA包裹 (plectonemic与solenoidal).
- 链裂变,旋转和重调的机械建模.
主要成果:
- 前进分辨率产生角Lk = +4;反向融合产生角Lk = -4.
- 反向反应需要较低的超螺旋密度,并产生未结合的产品.
- 链交换拓学表明,DNA复合体的180度旋转.
- 该机制涉及四个DNA链的溶解酶裂解,旋转和重组.
结论:
- Tn3溶解酶在DNA重组中采用一种特定的旋转机制.
- 酶的作用取决于DNA的超螺旋和包裹.
- 解析酶四聚体的D2对称模型解释了观察到的旋转.
- 这种机制不同于其他重组酶的机制,例如菌体兰巴巴整合酶.
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