Influence of histidine-198 of the D1 subunit on the properties of the primary electron donor, P680, of photosystem II in Thermosynechococcus elongatus.
Influence of histidine-198 of the D1 subunit on the properties of the primary electron donor, P680, of photosystem II in Thermosynechococcus elongatus.
复制标题
D1 亚基的组氨酸 198 对嗜热聚球藻光系统 II 的主要电子供体 P680 特性的影响。
DOI：
10.1016/j.bbabio.2008.01.007
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
F. Rappaport
中科院分区：
文献类型：
--
作者：
M. Sugiura;A. Boussac;T. Noguchi;F. Rappaport
组氨酸轴向配体的PD 1叶绿素的光系统II的氧化还原电位和光谱特性的主要电子供体，P680的影响，进行了研究，从嗜热蓝细菌细长热聚球藻纯化的突变体放氧光系统II（PSII）复合物。为了实现这一目标，开发了一种诱变系统，其中编码D1的psbA 1和psbA 2基因从His标记的CP 43菌株中缺失（以产生菌株WT p13），并将突变D1-H198 A和D1-H198 Q引入剩余的psbA 3基因中。发现从WT中分离的His-标记的PSII的O2-释放活性显著高于从WT中分离的His-标记的PSII测量的活性，其中psbA 1预期为主要表达形式。从D1-H198 A和D1-H198 Q突变体中纯化的PSII表现出与WT突变体一样高的放氧活性。令人惊讶的是，多种动力学和光谱测量显示D1-H198 A和D1-H198 Q突变对P680的氧化还原和光谱性质几乎没有影响，这与来自在集胞藻属PCC 6803中构建的等同突变体的分析的早期结果相反[B.A. Diner，E.放大图片作者：P. J.尼克松，W. J.科尔曼，F. Rappaport，J. Lavergne，W.F. Vermaas，DA.奇泽姆，集胞藻PCC 6803中光系统II的D1-His 198和D2-His 197的定点突变：初级电荷分离位点以及阳离子和三重态稳定化，生物化学40（2001）9265-9281]。我们的结论是，PD 1的轴向配体的性质是不是一个重要的决定因素的氧化还原和光谱性质的P680在T。细长的
The influence of the histidine axial ligand to the PD1chlorophyll of photosystem II on the redox potential and spectroscopic properties of the primary electron donor, P680,was investigated in mutant oxygen-evolving photosystem II (PSII) complexes purified from the thermophilic cyanobacterium Thermosynechococcus elongatus. To achieve this aim, a mutagenesis system was developed in which the psbA1and psbA2genes encoding D1 were deleted from a His-tagged CP43 strain (to generate strain WT⁎) and mutations D1-H198A and D1-H198Q were introduced into the remaining psbA3gene. The O2-evolving activity of His-tagged PSII isolated from WT⁎was found to be significantly higher than that measured from His-tagged PSII isolated from WT in which psbA1is expected to be the dominantly expressed form. PSII purified from both the D1-H198A and D1-H198Q mutants exhibited oxygen-evolving activity as high as that from WT⁎. Surprisingly, a variety of kinetic and spectroscopic measurements revealed that the D1-H198A and D1-H198Q mutations had little effect on the redox and spectroscopic properties of P680, in contrast to the earlier results from the analysis of the equivalent mutants constructed in Synechocystis sp. PCC 6803 [B.A. Diner, E. Schlodder, P.J. Nixon, W.J. Coleman, F. Rappaport, J. Lavergne, W.F. Vermaas, D.A. Chisholm, Site-directed mutations at D1-His198 and D2-His197 of photosystem II in Synechocystis PCC 6803: sites of primary charge separation and cation and triplet stabilization, Biochemistry 40 (2001) 9265–9281]. We conclude that the nature of the axial ligand to PD1is not an important determinant of the redox and spectroscopic properties of P680in T. elongatus.