The fission yeast rpa17+ gene encodes a functional homolog of AC19, a subunit of RNA polymerases I and III of Saccharomyces cerevisiae
The fission yeast rpa17+ gene encodes a functional homolog of AC19, a subunit of RNA polymerases I and III of Saccharomyces cerevisiae
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DOI：
10.1007/s004380050977
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发表时间：
1999-03-01
期刊：
影响因子：
--
通讯作者：
Nogi, Y
中科院分区：
文献类型：
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作者：
Imai, K;Imazawa, Y;Nogi, Y
真核RNA聚合酶I和III由多个亚基组成。这些酶中的每一种都包括两个独特的和进化上保守的亚基，称为α相关亚基，其仅由聚合酶I和III共享。α-相关亚基与原核RNA聚合酶的α-亚基显示出有限的同源性。为了进一步了解α相关亚基的结构和功能，我们克隆并表征了来自裂殖酵母的基因，该基因编码17 kDa的蛋白质，该蛋白质在功能上取代了酿酒酵母RNA聚合酶I和III的α相关亚基AC 19，因此命名为rpa 17（+）。RPA 17具有125个氨基酸，并且在108个残基的延伸上显示出与AC 19的63%的同一性，而两种蛋白质的N-末端区域是高度不同的。rpa 17（+）的破坏表明该基因是细胞生长所必需的。与来自不同物种的其他α相关亚基的序列比较表明，RPA 17包含进化上保守的81个氨基酸的块。RPA 17和AC 19的N-和C-末端区域的缺失分析证实了81个氨基酸的阻断对于α相关亚基的功能是重要的。
Eukaryotic RNA polymerases I and III consist of multiple subunits. Each of these enzymes includes two distinct and evolutionarily conserved subunits called alpha-related subunits which are shared only by polymerases I and III. The alpha-related subunits show limited homology with the alpha-subunit: of prokaryotic RNA polymerase. To gain further insight into the structure and function of alpha-related subunits, we cloned and characterized a gene from Schizosaccharomyces pombe that encodes a protein of 17 kDa which call functionally replace AC19 - an alpha-related subunit of RNA polymerases I and III of Saccharomyces cerevisiae - and was thus named rpa17(+). RPA17 has 125 amino acids and shows 63% identity to AC19 over a 108-residue stretch, whereas the N-terminal regions of the two proteins are highly divergent. Disruption of rpa17(+) shows that the gene is essential for cell growth. Sequence comparison with other alpha-related subunits from different species showed that RPA17 contains an 81-amino acid block that is evolutionarily conserved. Deletion analysis of the N- and C-terminal regions of RPA 17 and AC19 confirms that the 81-amino acid block is important for the function of the alpha-related subunits.