Wang X, Hansen S K, Ratts R, Zhou S, Snook A J, Zehring W
Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Proc Natl Acad Sci U S A. 1997 Jan 21;94(2):433-8. doi: 10.1073/pnas.94.2.433.
We present a physical and molecular genetic characterization of Drosophila melanogaster TFIIE (dTFIIE), a component of the basal RNA polymerase II transcription apparatus. We have purified dTFIIE to near homogeneity from nuclear extracts of Drosophila embryos and found that it is composed of two subunits with apparent molecular weights of 55 and 38 kDa. Peptide sequence information derived from the two subunits was used to isolate the corresponding cDNA clones, revealing that dTFIIE and human TFIIE share extensive amino acid similarity. Functional conservation was demonstrated by the ability of bacterially expressed dTFIIE to substitute for human TFIIE in an in vitro transcription assay reconstituted from purified components. Cytological mapping analysis shows that both subunits are encoded by single copy genes located on chromosome III.
我们展示了黑腹果蝇TFIIE（dTFIIE）的物理和分子遗传学特征，它是基础RNA聚合酶II转录装置的一个组成部分。我们已从果蝇胚胎的核提取物中纯化dTFIIE至近乎同质，并发现它由两个亚基组成，其表观分子量分别为55 kDa和38 kDa。源自这两个亚基的肽序列信息用于分离相应的cDNA克隆，揭示dTFIIE与人类TFIIE具有广泛的氨基酸相似性。在由纯化成分重构的体外转录测定中，细菌表达的dTFIIE能够替代人类TFIIE，这证明了功能保守性。细胞学图谱分析表明，这两个亚基均由位于第三条染色体上的单拷贝基因编码。
