Structural studies of E73 from a hyperthermophilic archaeal virus identify the "RH3" domain, an elaborated ribbon-helix-helix motif involved in DNA recognition.
Structural studies of E73 from a hyperthermophilic archaeal virus identify the "RH3" domain, an elaborated ribbon-helix-helix motif involved in DNA recognition.
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E73的结构性研究来自高疗细胞性古细菌病毒，鉴定了“ RH3”结构域，这是参与DNA识别的详细丝带螺旋螺旋基序。
DOI：
10.1021/bi201791s
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发表时间：
2012-04-03
期刊：
影响因子：
2.9
通讯作者：
Copie, Valerie
中科院分区：
文献类型：
--
作者：
Schlenker, Casey;Goel, Anupam;Tripet, Brian P.;Menon, Smita;Willi, Taylor;Dlakic, Mensur;Young, Mark J.;Lawrence, C. Martin;Copie, Valerie
超嗜热古细菌病毒包括梭形病毒SSV-1和锯齿山病毒SSV-1具有显著的形态和遗传多样性。然而，对它们的了解仍然很少，部分原因是它们的基因组与已知功能的基因表现出有限的或无法识别的序列相似性。在这里，我们报道了E73的结构和功能研究，E73是一个编码在ssv -褴褛山基因组中的73个残基的二聚体蛋白。尽管缺乏明显的序列相似性，但核磁共振结构显示出与许多参与转录调控的蛋白质中存在的带状-螺旋-螺旋（RHH）结构域明显相似。体外dsDNA结合实验证实了E73能够以微摩尔亲和力以非特异性方式结合dsDNA， K11E变体的表征证实了预测的DNA结合表面的位置。然而，E73不同于已知的RHHs。RHH基序通过插入与结构域紧密结合的第三个螺旋而得到详细阐述，从而产生“RH3”折叠。在同型二聚体中，这种螺旋导致在DNA结合表面远端形成一个保守的对称裂缝，在那里它可能介导蛋白质之间的相互作用，或有助于E73的高热稳定性。通过核磁共振对主链酰胺动力学的分析表明，在dna结合表面的反平行β-片区域内的残基具有刚性核和快速的ps-ns时间尺度的nhh键矢量运动，而在α1-α2环上的残基的时间尺度运动较慢μs至ms。讨论了E73及其SSV同源物在病毒生命周期中的作用。
Hyperthermophilic archaeal viruses including Sulfolobus spindle-shaped viruses (SSVs) such as SSV-1 and SSV-Ragged Hills exhibit remarkable morphology and genetic diversity. However, they remain poorly understood, in part because their genomes exhibit limited or unrecognizable sequence similarity to genes with known function. Here we report structural and functional studies of E73, a 73-residue homodimeric protein encoded within the SSV-Ragged Hills genome. Despite lacking significant sequence similarity, the NMR structure reveals clear similarity to ribbon-helix-helix (RHH) domains present in numerous proteins involved in transcriptional regulation. In vitro dsDNA binding experiments confirm the ability of E73 to bind dsDNA in a non-specific manner with micromolar affinity, and characterization of the K11E variant confirms the location of the predicted DNA binding surface. E73 is distinct, however, from known RHHs. The RHH motif is elaborated upon by the insertion of a third helix that is tightly integrated into the structural domain, giving rise to the “RH3” fold. Within the homodimer, this helix results in the formation of a conserved, symmetric cleft distal to the DNA binding surface, where it may mediate protein-protein interactions, or contribute to the high thermal stability of E73. Analysis of backbone amide dynamics by NMR provides evidence for a rigid core, and fast ps-ns timescale NH bond vector motions for residues located within the antiparallel β-sheet region of the proposed DNA-binding surface, and slower μs to ms timescale motions for residues in the α1-α2 loop. The role of E73 and its SSV homologs in the viral life cycle are discussed.
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影响因子：
3.6
作者：
Golovanov, AP;Barillà, D;Lian, LY
通讯作者：
Lian, LY
DOI：
10.1107/s0907444998003254
发表时间：
1998-09-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Brunger, AT;Adams, PD;Warren, GL
通讯作者：
Warren, GL
DOI：
10.1107/s0907444909042073
发表时间：
2010-01
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Chen VB;Arendall WB 3rd;Headd JJ;Keedy DA;Immormino RM;Kapral GJ;Murray LW;Richardson JS;Richardson DC
通讯作者：
Richardson DC
影响因子：
2.7
作者：
DELAGLIO, F;GRZESIEK, S;BAX, A
通讯作者：
BAX, A
影响因子：
3.7
作者：
Bath, Carolyn;Cukalac, Tania;Dyall-Smith, Michael L.
通讯作者：
Dyall-Smith, Michael L.