Feaver W J, Gileadi O, Li Y, Kornberg R D
Department of Cell Biology, Stanford University School of Medicine, California 94305.
Cell. 1991 Dec 20;67(6):1223-30. doi: 10.1016/0092-8674(91)90298-d.
A kinase activity specific for the C-terminal repeat domain (CTD) of RNA polymerase II is associated with nearly homogeneous yeast general initiation factor b by three criteria: cofractionation on the basis of size and charge and coinactivation by mild heat treatment. The kinase phosphorylates the CTD at multiple sites in a processive manner. Factor b may possess a DNA-dependent ATPase activity as well. Both kinase and DNA-dependent ATPase activities exhibit the same nucleotide requirements as previously demonstrated for the initiation of transcription. These results support the idea that phosphorylation of the CTD lies on the pathway of transcription initiation and identify a catalytic activity of a general factor essential for the initiation process.
一种对RNA聚合酶II的C末端重复结构域（CTD）具有特异性的激酶活性，通过三个标准与几乎均一的酵母通用起始因子b相关联：基于大小和电荷的共分级分离以及温和热处理导致的共失活。该激酶以连续的方式在多个位点磷酸化CTD。因子b可能也具有DNA依赖性ATP酶活性。激酶和DNA依赖性ATP酶活性都表现出与先前转录起始所证明的相同的核苷酸需求。这些结果支持了CTD磷酸化位于转录起始途径上的观点，并确定了起始过程中一个通用因子的催化活性。
