Zehring W A, Rothman-Denes L B
J Biol Chem. 1983 Jul 10;258(13):8074-80.
The soluble components of the RNA polymerase activity (N4 RNA polymerase II) required for coliphage N4 middle RNA synthesis have been purified to homogeneity using a complementation assay described elsewhere. These soluble components are found to exhibit the properties of a DNA-dependent RNA polymerase which is resistant to both rifampicin and streptolydigin and transcribes denatured N4 DNA with marked preference but with little selectivity for the middle region of the N4 genome. In its native form, the activity is composed of one Mr = 40,000 polypeptide (p4, the product of N4 cistron 4) and one Mr = 30,000 polypeptide (p7, the product of N4 cistron 3). Its physical properties and the mechanism of transcription selectivity are discussed.
利用在其他地方描述的互补测定法，已将噬菌体N4中期RNA合成所需的RNA聚合酶活性（N4 RNA聚合酶II）的可溶性成分纯化至同质。发现这些可溶性成分具有依赖DNA的RNA聚合酶的特性，该酶对利福平和平阳霉素均具有抗性，并且转录变性N4 DNA时对N4基因组的中间区域具有明显的偏好，但选择性很小。在其天然形式中，该活性由一个Mr = 40,000的多肽（p4，N4顺反子4的产物）和一个Mr = 30,000的多肽（p7，N4顺反子3的产物）组成。讨论了其物理性质和转录选择性机制。
