Kenzior A L, Folk W R
Department of Biochemistry, University of Missouri-Columbia, 65211, USA.
FEBS Lett. 1998 Dec 4;440(3):425-9. doi: 10.1016/s0014-5793(98)01500-2.
The mammalian RbAp48 protein is the most extensively studied member of the conserved family of Msi1-like WD-40 repeat proteins, which are components of complexes involved in the assembly and modification of chromatin. We have isolated a plant homolog of RbAp48, AtMSI4. By metal affinity chromatography, zinc blotting and atomic absorption analysis, we demonstrate that purified recombinant RbAp48 and AtMSI4 proteins bind 3-4 metal ions per molecule of protein. Metal competition assays indicate a preference for zinc. Both N- and C-terminal halves of RbAp48 and AtMSI4 display zinc binding activity, suggesting it is an intrinsic property of the propeller structures likely to be formed by these proteins. Metal binding might mediate and/or regulate protein-protein interactions which are functionally important in chromatin metabolism.
哺乳动物的RbAp48蛋白是保守的Msi1样WD-40重复蛋白家族中研究最为广泛的成员，这些蛋白是参与染色质组装和修饰的复合物的组成部分。我们分离出了RbAp48的植物同源物AtMSI4。通过金属亲和色谱、锌印迹和原子吸收分析，我们证明纯化的重组RbAp48和AtMSI4蛋白每分子蛋白质结合3 - 4个金属离子。金属竞争试验表明对锌有偏好。RbAp48和AtMSI4的N端和C端都显示出锌结合活性，这表明这可能是这些蛋白可能形成的螺旋桨结构的固有特性。金属结合可能介导和/或调节在染色质代谢中功能重要的蛋白质 - 蛋白质相互作用。
