Magill C P, Jackson S P, Bell S D
Wellcome Trust and Cancer Research Campaign Institute of Cancer and Developmental Biology, Tennis Court Road, Cambridge CB2 1QR, United Kingdom.
J Biol Chem. 2001 Dec 14;276(50):46693-6. doi: 10.1074/jbc.C100567200. Epub 2001 Oct 17.
Archaea possess two general transcription factors that are required to recruit RNA polymerase (RNAP) to promoters in vitro. These are TBP, the TATA-box-binding protein and TFB, the archaeal homologue of TFIIB. Thus, the archaeal and eucaryal transcription machineries are fundamentally related. In both RNAP II and archaeal transcription systems, direct contacts between TFB/TFIIB and the RNAP have been demonstrated to mediate recruitment of the polymerase to the promoter. However the subunit(s) directly contacted by these factors has not been identified. Using systematic yeast two-hybrid and biochemical analyses we have identified an interaction between the N-terminal domain of TFB and an evolutionarily conserved subunit of the RNA polymerase, RpoK. Intriguingly, homologues of RpoK are found in all three nuclear RNA polymerases (Rpb6) and also in the bacterial RNA polymerase (omega-subunit).
古菌拥有两种通用转录因子，它们是在体外将RNA聚合酶（RNAP）募集到启动子所必需的。这些因子是TBP（TATA框结合蛋白）和TFB（TFIIB的古菌同源物）。因此，古菌和真核生物的转录机制在根本上是相关的。在RNAP II和古菌转录系统中，TFB/TFIIB与RNAP之间的直接接触已被证明可介导聚合酶向启动子的募集。然而，尚未确定与这些因子直接接触的亚基。通过系统的酵母双杂交和生化分析，我们确定了TFB的N端结构域与RNA聚合酶的一个进化保守亚基RpoK之间存在相互作用。有趣的是，在所有三种核RNA聚合酶（Rpb6）以及细菌RNA聚合酶（ω亚基）中都发现了RpoK的同源物。
