ScII: an abundant chromosome scaffold protein is a member of a family of putative ATPases with an unusual predicted tertiary structure.
ScII: an abundant chromosome scaffold protein is a member of a family of putative ATPases with an unusual predicted tertiary structure.
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DOI：
10.1083/jcb.127.2.303
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发表时间：
1994-10
期刊：
影响因子：
--
通讯作者：
Earnshaw WC
中科院分区：
文献类型：
--
作者：
Saitoh N;Goldberg IG;Wood ER;Earnshaw WC
在这里，我们描述了在待鉴定的染色体支架部分中，仅次于拓扑异构酶II的第二丰富蛋白ScII的克隆和特性。在结构上，ScII与一种名为Smc1p的蛋白相关，Smc1p先前在酿酒酵母中被发现是精确的染色体分离所必需的。ScII和新出现的smc1样蛋白家族的其他成员可能是新型的atp酶，其与ntp结合的A和B位点被两个长区域分开，预计形成一个螺旋状的线圈。对ScII B位点的分析预测，ScII可能通过类似于细菌recN DNA修复和重组酶的机制使用ATP。ScII是一种有丝分裂特异性支架蛋白，与有丝分裂染色体中的拓扑异构酶II共定位。然而，ScII似乎与间期核基质无关。因此，ScII可能在染色体凝聚或姐妹染色单体分离等有丝分裂过程中发挥作用，这两种过程先前都被证明与拓扑异构酶II有关。
Here, we describe the cloning and characterization of ScII, the second most abundant protein after topoisomerase II, of the chromosome scaffold fraction to be identified. ScII is structurally related to a protein, Smc1p, previously found to be required for accurate chromosome segregation in Saccharomyces cerevisiae. ScII and the other members of the emerging family of SMC1-like proteins are likely to be novel ATPases, with NTP-binding A and B sites separated by two lengthy regions predicted to form an alpha-helical coiled-coil. Analysis of the ScII B site predicted that ScII might use ATP by a mechanism similar to the bacterial recN DNA repair and recombination enzyme. ScII is a mitosis-specific scaffold protein that colocalizes with topoisomerase II in mitotic chromosomes. However, ScII appears not to be associated with the interphase nuclear matrix. ScII might thus play a role in mitotic processes such as chromosome condensation or sister chromatid disjunction, both of which have been previously shown to involve topoisomerase II.