Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Photosynth Res. 2010 Jun;104(2-3):321-31. doi: 10.1007/s11120-009-9509-0. Epub 2010 Jan 22.
Heliobacteria and green sulfur bacteria have type I homodimeric reaction centers analogous to photosystem I. One remaining question regarding these homodimeric reaction centers is whether the structures and electron transfer reactions are truly symmetric or not. This question is relevant to the origin of the heterodimeric reaction centers, such as photosystem I and type II reaction centers. In this mini-review, Fourier transform infrared studies on the special pair bacteriochlorophylls, P798 in heliobacteria and P840 in green sulfur bacteria, are summarized. The data are reinterpreted in the light of the X-ray crystallographic structure of photosystem I and the sequence alignments of type I reaction center proteins, and discussed in terms of hydrogen bonding interactions and the symmetry of charge distribution over the dimer.
噬硫菌和绿硫菌具有类似于光系统 I 的 I 型同源二聚体反应中心。关于这些同源二聚体反应中心，仍有一个问题是它们的结构和电子转移反应是否真正对称。这个问题与异二聚体反应中心的起源有关，如光系统 I 和 II 型反应中心。在这篇迷你综述中，总结了关于噬硫菌中的特殊对细菌叶绿素 P798 和绿硫菌中的 P840 的傅里叶变换红外研究。根据光系统 I 的 X 射线晶体结构和 I 型反应中心蛋白的序列比对，重新解释了这些数据，并讨论了氢键相互作用和二聚体上电荷分布的对称性。
