Allosteric regulation of human poly(A)-specific ribonuclease by cap and potassium ions
Allosteric regulation of human poly(A)-specific ribonuclease by cap and potassium ions
复制标题
帽离子和钾离子对人多聚腺苷酸特异性核糖核酸酶的变构调节
DOI：
10.1016/j.bbrc.2008.12.056
复制
发表时间：
2009-02-06
影响因子：
3.1
通讯作者：
Yan, Yong-Bin
中科院分区：
文献类型：
--
作者：
Liu, Wei-Feng;Zhang, Ao;Yan, Yong-Bin
聚腺苷酸特异性核糖核酸酶（PARN）是一种多结构域二聚体酶，是高等脊椎动物和植物中的一种去腺苷酸酶，具有独特的帽依赖性催化和持续合成能力。我们发现PARN是一种变构酶，钾离子和帽类似物是效应物，其结合位点位于RRM结构域。K+与整个RRM结构域的结合导致底物结合亲和力的增加，但底物结合位点的协同性降低，而帽类似物的结合降低了催化效率和底物结合亲和力。具有和不具有整个RRM结构域的酶的不同动力学性质表明RRM结构域在PARN调节的变构通信中起核心作用。变构对于PARN的多水平调节以实现mRNA poly（A）尾长的精确控制是重要的。(c)2008年爱思唯尔公司All rights reserved.
Poly(A)-specific ribonuclease (PARN), a multi-domain dimeric enzyme, is a deadenylase in higher vertebrates and plants with the unique property of cap-dependent catalysis and processivity. We found that PARN is an allosteric enzyme, and potassium ions and the cap analogue were effectors with binding sites located at the RRM domain. The binding of K+ to the entire RRM domain led to an increase of substrate-binding affinity but a decrease in the cooperativity of the substrate-binding site, while the binding of the cap analogue decreased both the catalytic efficiency and the substrate-binding affinity. The dissimilar kinetic properties of the enzymes with and Without the entire RRM domain Suggested that the RRM domain played a central role in the allosteric communications of PARN regulation. The allostery is proposed to be important to the multi-level regulation of PARN to achieve precise control of the mRNA poly(A) tail length. (c) 2008 Elsevier Inc. All rights reserved.