Crystal structure of the 13-cis isomer of bacteriorhodopsin in the dark-adapted state
Crystal structure of the 13-cis isomer of bacteriorhodopsin in the dark-adapted state
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DOI：
10.1016/j.jmb.2005.07.021
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发表时间：
2005-09-16
影响因子：
5.6
通讯作者：
Kouyama, T
中科院分区：
文献类型：
--
作者：
Nishikawa, T;Murakami, M;Kouyama, T
细菌视紫红质的反式异构体的原子结构先前通过使用属于空间群P622的3D晶体确定。在这里，报道了在暗适应晶体中具有13-顺式，15-顺式视黄醛的另一种异构体的结构。这两种异构体的结构比较表明，视网膜异构化周围的C13=C14和C15=N键是伴随着显着的位移的一些残基附近的视网膜席夫碱和小的重新安排的氢键网络中的质子释放通道。另一方面，芳香族残基周围的视网膜多烯链被发现几乎没有移动在暗/光适应。这一结果表明，在视黄醇结合口袋内的结构刚性的变化是确保立体异构化的重要因素之一的视网膜。(c)2005爱思唯尔有限公司保留所有权利。
The atomic structure of the trans isomer of bacteriorhodopsin was determined previously by using a 3D crystal belonging to the space group P622. Here, a structure is reported for another isomer with the 13-cis, 15-syn retinal in a dark-adapted crystal. Structural comparison of the two isomers indicates that retinal isomerization around the C13=C14 and the C15=N bonds is accompanied by noticeable displacements of a few residues in the vicinity of the retinal Schiff base and small re-arrangement of the hydrogen-bonding network in the proton release channel. On the other hand, aromatic residues surrounding the retinal polyene chain were found to scarcely move during the dark/light adaptation. This result suggests that variation in the structural rigidity within the retinal-binding pocket is one of the important factors ensuring the stereospecific isomerization of retinal. (c) 2005 Elsevier Ltd. All rights reserved.