McKune K, Richards K L, Edwards A M, Young R A, Woychik N A
Roche Institute of Molecular Biology, Nutley, New Jersey 07110.
Yeast. 1993 Mar;9(3):295-9. doi: 10.1002/yea.320090309.
The Saccharomyces cerevisiae RNA polymerase II subunit gene RPB7 was isolated and sequenced. RPB7 is a single copy gene whose sequence predicts a 19,000 Dalton protein of 171 amino acids. RPB7 is known to dissociate from RNA polymerase II as an RPB4/RPB7 subcomplex in vitro. RPB7 also appears to interact with RNA polymerase II in a manner dependent upon RPB4, since RNA polymerase II purified from cells lacking RPB4 also lacks RPB7. Previous results have demonstrated that deletion of the RPB4 results in slow growth and cold- and temperature-sensitivity. In contrast, deletion of the RPB7 gene revealed that it is essential for cell growth and viability. Loss of both the RPB4 and the RPB7 genes causes lethality. These results suggest that RPB7 contributes to the function of RNA polymerase II in the absence of RPB4 either in a manner independent of its association with the enzyme or by directly binding to the enzyme in a manner independent of its association with RPB4.
酿酒酵母RNA聚合酶II亚基基因RPB7被分离并测序。RPB7是一个单拷贝基因，其序列预测编码一个由171个氨基酸组成的19,000道尔顿的蛋白质。已知在体外，RPB7会作为RPB4/RPB7亚复合物从RNA聚合酶II上解离。RPB7似乎还以一种依赖于RPB4的方式与RNA聚合酶II相互作用，因为从缺乏RPB4的细胞中纯化得到的RNA聚合酶II也缺乏RPB7。先前的结果表明，缺失RPB4会导致生长缓慢以及对低温和温度敏感。相比之下，缺失RPB7基因表明它对细胞生长和活力至关重要。同时缺失RPB4和RPB7基因会导致致死性。这些结果表明，在缺乏RPB4的情况下，RPB7要么以一种与其与酶的结合无关的方式，要么通过以一种与其与RPB4的结合无关的方式直接结合到酶上，从而对RNA聚合酶II的功能有所贡献。
