The dUTPase of white spot syndrome virus assembles its active sites in a noncanonical manner
The dUTPase of white spot syndrome virus assembles its active sites in a noncanonical manner
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白斑综合症病毒的 dUTPase 以非规范方式组装其活性位点
DOI：
10.1074/jbc.m117.815266
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发表时间：
2017-11
影响因子：
4.8
通讯作者：
Ma Qingjun
中科院分区：
文献类型：
--
作者：
Zang Kun;Li Fuhua;Ma Qingjun
dUTPases是维持基因组完整性所必需的酶，并且最近已显示当含有额外序列时发挥兼职作用。有趣的是，白色斑点综合征病毒（wDUT）的三聚体dUTPases在C-末端催化基序V（前V插入）之前的位置处含有序列插入，这在其他dUTPases中很少见。然而，这个额外的序列是否赋予wDUT额外的属性是未知的。在这里，我们提出了wDUT的晶体结构在无配体和配体结合的形式。我们观察到wDUT中的pre-V插入物在结构域交换区形成了一个不寻常的β-发夹结构，从而促进了相邻C-末端片段的独特取向，将催化基序V定位在其自身亚基而不是第三个亚基的活性位点上。因此，wDUT采用两个亚基的活性位点，不像广泛接受的范式，即三聚体dUTR的活性位点由所有三个亚基贡献。根据局部结构比较的结果，wDUT的活性位点构型与已知dUTPases的活性位点构型相似。然而，我们还发现，在第二壳区的活性位点的残基被重新配置在wDUT作为其独特的C-末端方向的适应。我们还表明，删除前V插入显着降低wDUT的酶活性和热稳定性。我们假设这种罕见的结构安排赋予wDUT额外的功能。总之，我们的研究扩展了保守的dUTR家族的结构多样性，并说明了序列插入和氨基酸取代如何协同驱动蛋白质进化。
dUTPases are essential enzymes for maintaining genome integrity and have recently been shown to play moonlighting roles when containing extra sequences. Interestingly, the trimeric dUTPase of white spot syndrome virus (wDUT) harbors a sequence insert at the position preceding the C-terminal catalytic motif V (pre-V insert), rarely seen in other dUTPases. However, whether this extra sequence endows wDUT with additional properties is unknown. Herein, we present the crystal structures of wDUT in both ligand-free and ligand-bound forms. We observed that the pre-V insert in wDUT forms an unusual β-hairpin structure in the domain-swapping region and thereby facilitates a unique orientation of the adjacent C-terminal segment, positioning the catalytic motif V onto the active site of its own subunit instead of a third subunit. Consequently, wDUT employs two-subunit active sites, unlike the widely accepted paradigm that the active site of trimeric dUTPase is contributed by all three subunits. According to results from local structural comparisons, the active-site configuration of wDUT is similar to that of known dUTPases. However, we also found that residues in the second-shell region of the active site are reconfigured in wDUT as an adaption to its unique C-terminal orientation. We also show that deletion of the pre-V insert significantly reduces wDUT's enzymatic activity and thermal stability. We hypothesize that this rare structural arrangement confers additional functionality to wDUT. In conclusion, our study expands the structural diversity in the conserved dUTPase family and illustrates how sequence insertion and amino acid substitution drive protein evolution cooperatively.
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DOI：
10.1107/s0907444910045749
发表时间：
2011-04
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Winn MD;Ballard CC;Cowtan KD;Dodson EJ;Emsley P;Evans PR;Keegan RM;Krissinel EB;Leslie AG;McCoy A;McNicholas SJ;Murshudov GN;Pannu NS;Potterton EA;Powell HR;Read RJ;Vagin A;Wilson KS
通讯作者：
Wilson KS
影响因子：
--
作者：
Kim R;Guo JT
通讯作者：
Guo JT
影响因子：
18.3
作者：
Vertessy, Beata G.;Toth, Judit
通讯作者：
Toth, Judit
DOI：
10.1073/pnas.1013872108
发表时间：
2011-08-30
影响因子：
11.1
作者：
Pecsi, Ildiko;Szabo, Judit E.;Toth, Judit
通讯作者：
Toth, Judit
影响因子：
11.4
作者：
GADSDEN, MH;MCINTOSH, EM;HAYNES, RH
通讯作者：
HAYNES, RH