Factor requirements for transcription in the Archaeon Sulfolobus shibatae
Factor requirements for transcription in the Archaeon Sulfolobus shibatae
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DOI：
10.1093/emboj/16.10.2927
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发表时间：
1997-05-15
期刊：
影响因子：
11.4
通讯作者：
Jackson, SP
中科院分区：
文献类型：
--
作者：
Qureshi, SA;Bell, SD;Jackson, SP
古生菌（Archaea，古细菌）构成了一个不同于细菌（真细菌）和真核生物（真核生物）的生命域，尽管古生菌细胞与真细菌有许多共同的形态学特征，但它们的转录装置更类似于真核生物的RNA聚合酶I、II和III，而不是真细菌的转录系统。因此，除了具有10亚基RNA聚合酶和塔塔结合蛋白（TBP）的同源物外，古细菌具有一种称为TFB的多肽，与真核生物TFIIB同源。在这里，我们研究了古细菌Sulfolobus shibatae及其相关病毒SSV的几个启动子转录的因子需求。通过体外转录和免疫缺失，我们发现柴田皂苷TBP、TFB和RNA聚合酶之间的复合物并不紧密，并且每一个都是有效转录所测试的所有启动子所必需的。此外，通过补充重组TBP或TFB来恢复完全转录，这表明不需要TBP相关因子或TFB相关因子。凝胶过滤表明，Sulfolobus TBP和TFB与其他蛋白质不稳定相关。最后，所有分析的启动子都在一个由重组TBP和TFB组成的体外系统中准确有效地转录，以及基本均匀的RNA聚合酶制备。因此，古细菌的转录基本上与真核生物的转录同源，尽管因子需求似乎要简单得多。
Archaea (archaebacteria) constitute a domain of life that is distinct from Bacteria (eubacteria) and Eucarya (eukaryotes), Although archaeal cells share many morphological features with eubacteria, their transcriptional apparatus is more akin to eukaryotic RNA polymerases I, II and III than it is to eubacterial transcription systems, Thus, in addition to possessing a 10 subunit RNA polymerase and a homologue of the TATA-binding protein (TBP), Archaea possess a polypeptide termed TFB that is homologous to eukaryotic TFIIB, Here, we investigate the factor requirements for transcription of several promoters of the archaeon Sulfolobus shibatae and its associated virus SSV. Through in vitro transcription and immunodepletion, we demonstrate that S. shibatae TBP, TFB and RNA polymerase are not complexed tightly with one another and that each is required for efficient transcription of all promoters tested, Furthermore, full transcription is restored by supplementing respective depleted extracts with recombinant TBP or TFB, indicating that TBP-associated factors or TFB-associated factors are not required, Indeed, gel-filtration suggests that Sulfolobus TBP and TFB are not associated stably with other proteins, Finally, all promoters analysed are transcribed accurately and efficiently in an in vitro system comprising recombinant TBP and TFB, together with essentially homogeneous preparation of RNA polymerase, Transcription in Archaea is therefore fundamentally homologous to that in eukaryotes, although factor requirements appear to be much less complex.