Shuey D J, Attardi G
J Biol Chem. 1985 Feb 10;260(3):1952-8.
An RNA polymerase activity capable of initiating transcription at both the heavy strand rRNA promoter and the light strand promoter of human mitochondrial DNA has been partially purified from HeLa cell mitochondria and characterized in its requirements and products. The ratio of the two transcription initiating activities varied considerably from preparation to preparation. The human mtRNA polymerase partially purified by DEAE-cellulose and heparin-agarose chromatography exhibits a great sensitivity to ionic strength and to Mn2+, characteristics which clearly differentiate this enzyme from bacterial and eukaryotic nuclear RNA polymerases, and in contrast resemble the behavior of the yeast mtRNA polymerase. The human mtRNA polymerase exhibits a requirement for ATP which is 15- to 20-fold higher than that for the other NTPs, a low optimum template DNA concentration, and a marked susceptibility to inhibition by non-mitochondrial DNA.
一种能够在人类线粒体DNA的重链rRNA启动子和轻链启动子处起始转录的RNA聚合酶活性已从HeLa细胞线粒体中得到部分纯化，并对其需求和产物进行了表征。两种转录起始活性的比例在不同制备物之间有很大差异。通过DEAE-纤维素和肝素-琼脂糖色谱法部分纯化的人类线粒体RNA聚合酶对离子强度和Mn2+表现出极大的敏感性，这些特性使其与细菌和真核细胞核RNA聚合酶明显区分开来，相反，类似于酵母线粒体RNA聚合酶的行为。人类线粒体RNA聚合酶对ATP的需求比对其他NTPs高15至20倍，最佳模板DNA浓度较低，并且对非线粒体DNA的抑制作用明显敏感。
