Schizosaccharomyces pombe Ribonuclease P

描述（由申请人提供）：核糖核酸酶P（RNase P）是一种 核糖核蛋白颗粒（RNP），其在前体tRNA的加工中起作用。 虽然RNase P是必需的，存在于所有细胞中，但这种RNP的结构 表现出相当大的多样性。细菌全酶由一个大的 RNA分子和小多肽。细菌核糖核酸酶P RNA已被证明 是一种核酶，也就是说，RNA在没有蛋白质的情况下是催化的。在 相比之下，来自芽殖酵母酿酒酵母的全酶是 显示由RNA分子和至少九种多肽组成。活性 真核生物在没有蛋白质的情况下， 演示。另一种真核核糖核酸酶P的组成， 酵母裂殖酵母，已经预测是非常不同的， 由RNA分子和单个100 kD多肽组成。然而，在这方面， S.已经鉴定了酿酒酵母RNase P蛋白， 在粟酒裂殖酵母基因组中，这表明这些酶可能比 最初相信。这个建议需要一个更完整的生化 分离纯化及鉴定。pombe RNase P.的功能， S.粟酒孢RNase P蛋白将通过两种生物化学方法进行研究。 重组实验和遗传缺失分析。纯化和 对S. pombe RNase P将为进一步研究提供基础。 真核核糖核酸酶P的复杂性研究

DESCRIPTION (provided by applicant): Ribonuclease P (RNase P) is a ribonucleoprotein particle (RNP) that functions in the processing of pre-tRNAs. While RNase P is essential and present in all cells, the structure of this RNP exhibits considerable diversity. The bacterial holoenzyme consists of a large RNA molecule and a small polypeptide. The bacterial RNase P RNA has been shown to be a ribozyme, that is, the RNA is catalytic in the absence of protein. In contrast, the holoenzyme from the budding yeast Saccharomyces cerevisiae was shown to consist of an RNA molecule and at least nine polypeptides. Activity of RNase P RNA from eucaryotes in the absence of protein has never been demonstrated. The composition of another eucaryal RNase P, that of the fission yeast Schizosaccharomyces pombe, has been predicted to be very different, consisting of an RNA molecule and a single 100 kD polypeptide. However, homologs of several of the S. cerevisiae RNase P proteins have been identified in the S pombe genome suggesting these enzymes may be more similar than initially believed. This proposal entails a more complete biochemical purification and characterization of the S. pombe RNase P. The function of the S. pombe RNase P proteins will be investigated by both biochemical reconstitution experiments and genetic deletion analysis. The purification and characterization of the S. pombe RNase P will provide groundwork for further study of the complexity of eucaryal RNase P.