An atypical topoisomerase II from archaea with implications for meiotic recombination
An atypical topoisomerase II from archaea with implications for meiotic recombination
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DOI：
10.1038/386414a0
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发表时间：
1997-03-27
期刊：
影响因子：
64.8
通讯作者：
Forterre, P
中科院分区：
文献类型：
--
作者：
Bergerat, A;deMassy, B;Forterre, P
II型拓扑异构酶通过短暂的双链断裂催化DNA链转移，帮助调节转录、复制和重组过程中的DNA拓扑结构（1）。迄今为止描述的所有II型拓扑异构酶都是单个蛋白质家族的成员（2）。我们克隆了芝田硫化叶菌拓扑异构酶Ⅱ A和B亚基的编码基因并进行了序列测定。这种酶是一个新家族的第一个。除了B亚基中可能参与ATP结合和水解的三个基序外，它与其他II型拓扑异构酶没有相似性。我们还在Hsp90（3）和MutL（4）家族的蛋白质中发现了这些基序。A亚基与四种功能未知的蛋白质具有相似性。其中之一，酿酒酵母Spo11（5）蛋白，是减数分裂重组启动所必需的。突变，SPO11上进行的，单一的酪氨酸之间的五个同源物的保守性表明，这种氨基酸是必不可少的Spo11活性。通过与已知的II型拓扑异构酶的作用机制进行类比，我们认为Spell催化形成双链断裂，启动S. cerebralae。
Type II topoisomerases help regulate DNA topology during transcription, replication and recombination by catalysing DNA strand transfer through transient double-stranded breaks(1). All type II topoisomerases described so far are members of a single protein family(2). We have cloned and sequenced the genes encoding the A and B subunits of topoisomerase II from the archaeon Sulfolobus shibatae. This enzyme is the first of a new family. It has no similarity with other type II topoisomerases, except for three motifs in the B subunit probably involved in ATP binding and hydrolysis. We also found these motifs in proteins of the Hsp90(3) and MutL(4) families. The A subunit has similarities with four proteins of unknown function. One of them, the Saccharomyces cerevisiae Spo11(5) protein, is required for the initiation of meiotic recombination. Mutagenesis, performed on SPO11, of the single tyrosine conserved between the five homologues shows that this amino acid is essential for Spo11 activity. By analogy with the mechanism of action of known type II topoisomerases, we suggest that Spell catalyses the formation of double-strand breaks that initiate meiotic recombination in S. cervisiae.