Dissimilar roles of the four conserved acidic residues in the thermal stability of poly(A)-specific ribonuclease.
Dissimilar roles of the four conserved acidic residues in the thermal stability of poly(A)-specific ribonuclease.
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四个保守酸性残基在聚 (A) 特异性核糖核酸酶热稳定性中的不同作用
DOI：
10.3390/ijms12052901
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发表时间：
2011
影响因子：
5.6
通讯作者：
Yan YB
中科院分区：
文献类型：
--
作者：
He GJ;Liu WF;Yan YB
二价金属离子对于许多核苷酸转移酶的高效催化和结构稳定性是必不可少的。Poly(A)特异性核糖核酸酶(Parn)属于DEDD超家族的3‘-核酸外切酶，其活性部位含有四个保守的酸性氨基酸残基，配位两个镁离子。在本研究中，我们通过突变分析研究了这四个酸性残基在PARN热稳定性中的作用。结果发现，镁离子以浓度依赖的方式显著降低54 kDa野生型PARN的速率，增加其聚集体大小。这四个突变体都降低了PARN的热聚集，但其聚集动力学表现出不同的镁离子依赖行为。动力学参数的比较表明，Asp28对两种镁离子的结合最为关键，而金属B在PARN结构稳定性中可能起更重要的作用。光谱和聚集结果还表明，金属结合或突变导致活性中心结构的变化可能导致PARN分子的整体构象变化。
Divalent metal ions are essential for the efficient catalysis and structural stability of many nucleotidyl-transfer enzymes. Poly(A)-specific ribonuclease (PARN) belongs to the DEDD superfamily of 3′-exonucleases, and the active site of PARN contains four conserved acidic amino acid residues that coordinate two Mg2+ ions. In this research, we studied the roles of these four acidic residues in PARN thermal stability by mutational analysis. It was found that Mg2+ significantly decreased the rate but increased the aggregate size of the 54 kDa wild-type PARN in a concentration-dependent manner. All of the four mutants decreased PARN thermal aggregation, while the aggregation kinetics of the mutants exhibited dissimilar Mg2+-dependent behavior. A comparison of the kinetic parameters indicated that Asp28 was the most crucial one to the binding of the two Mg2+ ions, while metal B might be more important in PARN structural stability. The spectroscopic and aggregation results also suggested that the alterations in the active site structure by metal binding or mutations might lead to a global conformational change of the PARN molecule.
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影响因子：
14.9
作者：
Sissi C;Palumbo M
通讯作者：
Palumbo M
DOI：
10.1073/pnas.212527999
发表时间：
2002-12-10
影响因子：
11.1
作者：
Chiti, F;Calamai, M;Dobson, CM
通讯作者：
Dobson, CM
影响因子：
4.8
作者：
Menéndez, M;Rivas, G;Andreu, JM
通讯作者：
Andreu, JM
影响因子：
11.4
作者：
BEESE, LS;STEITZ, TA
通讯作者：
STEITZ, TA
R3H 结构域通过稳定 RRM 结构域来稳定聚腺苷酸特异性核糖核酸酶
DOI：
10.1016/j.bbrc.2007.06.139
发表时间：
2007-09-07
影响因子：
3.1
作者：
Liu, Wei-Feng;Zhang, Ao;Yan, Yong-Bin
通讯作者：
Yan, Yong-Bin