3D Structures of Plant Phytochrome A as Pr and Pfr From Solid-State NMR: Implications for Molecular Function.
3D Structures of Plant Phytochrome A as Pr and Pfr From Solid-State NMR: Implications for Molecular Function.
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DOI：
10.3389/fpls.2018.00498
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发表时间：
2018
影响因子：
5.6
通讯作者：
Hughes J
中科院分区：
文献类型：
--
作者：
Song C;Mroginski MA;Lang C;Kopycki J;Gärtner W;Matysik J;Hughes J
我们目前的结构信息燕麦phyA 3在远红光吸收（PFR）信号状态，据我们所知的第一个三维（3D）的植物光敏色素PFR的信息。固态魔角旋转（MAS）NMR用于检测完整光敏模块[残基1-595，包括NTE]中的原子间接触（N-末端延伸），PAS（Per/Arnt/Sim），GAF（cGMP磷酸二酯酶/腺苷酸环化酶/FhlA）和PHY（光敏色素特异性）结构域，但C-末端PAS重复和传递蛋白样模块缺失]在体外与13 C-和15 N-标记的藻蓝胆素（PCB）发色团。此后，量子力学/分子力学（QM/MM）使我们能够改进由NMR数据约束的3D结构模型。我们为发色团的所有碳和氮原子提供了明确的原子分配，显示Pfr发色团几何形状为周面ZZEssa，其中D-环处于β-面配置，与许多早期关于光转换的概念不相容，但支持圆二色性（CD）数据。Y268侧链相对于已发表的Pfr晶体结构发生了根本性位移，以容纳β-面环D。我们的研究结果支持了一个光转化序列，该序列始于Pr通过反式D环Za→Ea光翻转的光活化，随后是A环与蛋白质偶联的显著变化，B环丙酸酯伴侣从R317交换到R287，C环丙酸酯氢键网络的变化，D272-R552盐桥的断裂伴随着由Y326-D272-S554氢键稳定的舌区域的片-螺旋重折叠，以及NTE与环A的疏水侧的结合。我们讨论了phyA的光转换，包括可能的作用，在生色团口袋中的介观相变和质子化动力学。我们还讨论了结构变化和易位和细胞内的信号传导过程之间可能存在的关联。
We present structural information for oat phyA3 in the far-red-light-absorbing (Pfr) signaling state, to our knowledge the first three-dimensional (3D) information for a plant phytochrome as Pfr. Solid-state magic-angle spinning (MAS) NMR was used to detect interatomic contacts in the complete photosensory module [residues 1–595, including the NTE (N-terminal extension), PAS (Per/Arnt/Sim), GAF (cGMP phosphodiesterase/adenylyl cyclase/FhlA) and PHY (phytochrome-specific) domains but with the C-terminal PAS repeat and transmitter-like module deleted] auto-assembled in vitro with 13C- and 15N-labeled phycocyanobilin (PCB) chromophore. Thereafter, quantum mechanics/molecular mechanics (QM/MM) enabled us to refine 3D structural models constrained by the NMR data. We provide definitive atomic assignments for all carbon and nitrogen atoms of the chromophore, showing the Pfr chromophore geometry to be periplanar ZZEssa with the D-ring in a β-facial disposition incompatible with many earlier notions regarding photoconversion yet supporting circular dichroism (CD) data. The Y268 side chain is shifted radically relative to published Pfr crystal structures in order to accommodate the β-facial ring D. Our findings support a photoconversion sequence beginning with Pr photoactivation via an anticlockwise D-ring Za→Ea photoflip followed by significant shifts at the coupling of ring A to the protein, a B-ring propionate partner swap from R317 to R287, changes in the C-ring propionate hydrogen-bonding network, breakage of the D272–R552 salt bridge accompanied by sheet-to-helix refolding of the tongue region stabilized by Y326–D272–S554 hydrogen bonding, and binding of the NTE to the hydrophobic side of ring A. We discuss phyA photoconversion, including the possible roles of mesoscopic phase transitions and protonation dynamics in the chromophore pocket. We also discuss possible associations between structural changes and translocation and signaling processes within the cell.
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影响因子：
4.5
作者：
Genoud, Thierry;Schweizer, Fabian;Tscheuschler, Anke;Debrieux, Dimitry;Casal, Jorge J.;Schaefer, Eberhard;Hiltbrunner, Andreas;Fankhauser, Christian
通讯作者：
Fankhauser, Christian
DOI：
10.1073/pnas.0407645101
发表时间：
2004-12-14
影响因子：
11.1
作者：
Fischer, AJ;Lagarias, JC
通讯作者：
Lagarias, JC
影响因子：
3.3
作者：
Escobar, Francisco Velazquez;Buhrke, David;Hildebrandt, Peter
通讯作者：
Hildebrandt, Peter
影响因子：
5.4
作者：
Hahn, J;Strauss, HM;Hughes, J
通讯作者：
Hughes, J
影响因子：
15
作者：
Bhoo, SH;Hirano, T;Song, PS
通讯作者：
Song, PS