DNA wrapping and bending by a mitochondrial high mobility group-like transcriptional activator protein.
DNA wrapping and bending by a mitochondrial high mobility group-like transcriptional activator protein.
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DOI：
10.1016/s0021-9258(19)50739-6
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发表时间：
1992-02
期刊：
影响因子：
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通讯作者：
R. Fisher;Thomas LisowskySlI;Melissa A. Parisill;D. Clayton
中科院分区：
文献类型：
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作者：
R. Fisher;Thomas LisowskySlI;Melissa A. Parisill;D. Clayton
线粒体转录因子 1 (mtTF1) 是哺乳动物线粒体 RNA 聚合酶准确有效识别启动子所需的唯一已知辅助蛋白。它通过紧邻转录起始位点的上游结合来激活转录，并在初级 DNA 序列要求中显示出固有的灵活性。通过应用针对人类和小鼠 mtTF1 设计的纯化策略，最近从酵母线粒体中分离出了一种类似于 mtTF1 的蛋白质；它的大小（19 kDa）、DNA 结合特性和氨基酸组成表明与 HM 相同，HM 是一种先前描述的酵母线粒体丰富的蛋白质。人类和酵母蛋白都表现出在体外包裹、压缩和解开 DNA 以及以特定序列弯曲 DNA 的一般能力。最近对人类和酵母蛋白的氨基酸序列的测定表明，两者都含有与核高迁移率基团（HMG）蛋白同源的结构域，这些结构域涉及多种功能，例如染色质压缩和转录刺激。解开和弯曲 DNA 的能力可能是哺乳动物蛋白在线粒体 DNA 转录和复制启动中所记录的作用的基础，并表明酵母蛋白在酵母线粒体中具有类似的功能。
Mitochondrial transcription factor 1 (mtTF1) is the only accessory protein known to be required for accurate and efficient promoter recognition by mammalian mitochondrial RNA polymerase. It activates transcription by binding immediately upstream of transcriptional start sites and shows an inherent flexibility in primary DNA sequence requirement. By application of a purification strategy designed for human and mouse mtTF1, a protein resembling mtTF1 was recently isolated from yeast mitochondria; its size (19 kDa), DNA-binding properties, and amino acid composition suggest identity to HM, a previously described abundant protein of yeast mitochondria. Both human and yeast proteins show a general ability to wrap or condense and unwind DNA in vitro and bend DNA at specific sequences. Recent determinations of the amino acid sequences of the human and yeast proteins reveal that both contain domains homologous to the nuclear high mobility group (HMG) proteins which have been implicated in diverse functions such as chromatin compaction and transcription stimulation. The ability to unwind and bend DNA may be fundamental to the documented roles of the mammalian protein in mitochondrial DNA transcription and replication priming and suggests a similar function for the yeast protein in yeast mitochondria.