Replication factors MCM2 and ORC1 interact with the histone acetyltransferase HBO1
Replication factors MCM2 and ORC1 interact with the histone acetyltransferase HBO1
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DOI：
10.1074/jbc.m011556200
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发表时间：
2001-05-04
影响因子：
4.8
通讯作者：
Nevins, JR
中科院分区：
文献类型：
--
作者：
Burke, TW;Cook, JG;Nevins, JR
微小染色体维持（MCM）蛋白、起始点识别复合物（ORC）蛋白和Cdc 6通过在复制起始点形成复制前复合物在真核DNA复制中起重要作用。我们使用酵母双杂交筛选来鉴定MCM 2相互作用蛋白。我们鉴定的一种蛋白质与称为HBO 1的ORC 1相互作用蛋白相同。HBO 1属于MYST家族，其特征在于高度保守的C2 HC锌指和推定的组蛋白乙酰转移酶结构域。生物化学研究证实了MCM 2和HBO 1在体外和体内的相互作用。MCM 2的N-末端结构域对于结合HBO 1是必需的，HBO 1的C2 HC锌指对于结合MCM 2是必需的。进行反向酵母双杂交选择以分离与HBO 1相互作用有缺陷的MCM 2等位基因;然后使用该等位基因分离恢复与突变MCM 2相互作用的HBO 1抑制突变体。这种抑制突变位于HBO 1锌指。综上所述，这些发现强烈表明，MCM 2和HBO 1之间的相互作用是直接的，并通过HBO 1的C2 HC锌指介导。MYST家族蛋白HBO 1与复制装置的两个组成部分MCM 2和ORC 1的生物化学和遗传相互作用表明，HBO 1相关的HAT活性可能在DNA复制过程中发挥直接作用。
The minichromosome maintenance (MCM) proteins, together with the origin recognition complex (ORC) proteins and Cdc6, play an essential role in eukaryotic DNA replication through the formation of a pre-replication complex at origins of replication. We used a yeast two-hybrid screen to identify MCM2-interacting proteins. One of the proteins we identified is identical to the ORC1-interacting protein termed HBO1. HBO1 belongs to the MYST family, characterized by a highly conserved C2HC zinc finger and a putative histone acetyltransferase domain. Biochemical studies confirmed the interaction between MCM2 and HBO1 in vitro and in vivo. An N-terminal domain of MCM2 is necessary for binding to HBO1, and a C2HC zinc finger of HBO1 is essential for binding to MCM2. A reverse yeast two-hybrid selection was performed to isolate an allele of MCM2 that is defective for interaction with HBO1; this allele was then used to isolate a suppressor mutant of HBO1 that restores the interaction with the mutant MCM2. This suppressor mutation was located in the HBO1 zinc finger. Taken together, these findings strongly suggest that the interaction between MCM2 and HBO1 is direct and mediated by the C2HC zinc finger of HBO1. The biochemical and genetic interactions of MYST family protein HBO1 with two components of the replication apparatus, MCM2 and ORC1, suggest that HBO1-associated HAT activity may play a direct role in the process of DNA replication.