Characterization of a triple DNA polymerase replisome
Characterization of a triple DNA polymerase replisome
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DOI：
10.1016/j.molcel.2007.06.019
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发表时间：
2007-08-17
期刊：
影响因子：
16
通讯作者：
O'Donnell, Mike
中科院分区：
文献类型：
--
作者：
McInerney, Peter;Johnson, Aaron;O'Donnell, Mike
所有细胞的复制酶都被认为是利用两种DNA聚合酶来协调合成前导链和滞后链。DNA聚合酶通过圆形滑动夹固定在DNA上。我们在这里证明，大肠杆菌DNA聚合酶III全酶组装成一个粒子，其中包含三个DNA聚合酶。这三种聚合酶似乎能够同时发挥活性。此外，三聚体复制酶在带有解旋酶、引物酶和滑动夹的复制叉上完全发挥功能；它产生的冈崎片段比含有两种DNA聚合酶的复制体稍短。我们提出两种聚合酶可以在滞后链上起作用，第三种DNA聚合酶可以作为一种储备酶来克服复制叉的某些类型的障碍。
The replicase of all cells is thought to utilize two DNA polymerases for coordinated synthesis of leading and lagging strands. The DNA polymerases are held to DNA by circular sliding clamps. We demonstrate here that the E. coli DNA polymerase III holoenzyme assembles into a particle that contains three DNA polymerases. The three polymerases appear capable of simultaneous activity. Furthermore, the trimeric replicase is fully functional at a replication fork with helicase, primase, and sliding clamps; it produces slightly shorter Okazaki fragments than replisomes containing two DNA polymerases. We propose that two polymerases can function on the lagging strand and that the third DNA polymerase can act as a reserve enzyme to overcome certain types of obstacles to the replication fork.