Abstract：
During DNA replication, core histones that form nucleosomes on template strands are evicted and associate with newly synthesized strands to reform nucleosomes. Mcm2, a subunit of the Mcm2-7 complex, which is a core component of the replicative helicase, interacts with histones in the amino-terminal region (Mcm2N) and is involved in the parental histone recycling to lagging strands. Herein, the interaction of Mcm2N with histones was biochemically analyzed to reveal the molecular mechanisms underlying histone recycling by Mcm2N. With the addition of Mcm2N, a histone hexamer, comprising a H3-H4 tetramer and a H2A-H2B dimer, was excised from the histone octamer to form a complex with Mcm2N. The histone hexamer, but not H3-H4 tetramer was released from Mcm2N in the presence of Nap1, a histone chaperone. FACT, another histone chaperone, stabilized Mcm2N-histone hexamer complex to protect from Nap1-dependent dissociation. This study indicates cooperative histone transfer via Mcm2N and histone chaperones.
摘要：
在DNA复制过程中,在模板链上形成核小体的核心组蛋白被驱逐并与新合成的链结合以重新形成核小体。Mcm2是Mcm2-7复合体的一个亚单位,这是复制解旋酶的核心组成部分，与氨基末端区域（Mcm2N）中的组蛋白相互作用，并参与亲本组蛋白向滞后链的再循环。在这里，对Mcm2N与组蛋白的相互作用进行了生化分析，以揭示Mcm2N组蛋白再循环的分子机制。随着Mcm2N的加入，一个组蛋白六聚体，包含H3-H4四聚体和H2A-H2B二聚体，从组蛋白八聚体中切除，与Mcm2N形成复合物。组蛋白六聚体，但在组蛋白伴侣Nap1存在下，Mcm2N不会释放H3-H4四聚体。事实上,另一个组蛋白伴侣,稳定的Mcm2N-组蛋白六聚体复合物以防止Nap1依赖性解离。这项研究表明，通过Mcm2N和组蛋白伴侣进行协同组蛋白转移。
