Arnoux B, Ducruix A, Reiss-Husson F, Lutz M, Norris J, Schiffer M, Chang C H
Institut de Chimie des Substances Naturelles, UPR 407, CNRS, Gif sur Yvette, France.
FEBS Lett. 1989 Nov 20;258(1):47-50. doi: 10.1016/0014-5793(89)81612-6.
The structure of the reaction center of Y Rhodobacter sphaeroides has been solved at 3 A resolution, using the atomic coordinates of the reaction center from the carotenoidless mutant R26 Rhodobacter sphaeroides. The structure has been refined by a stimulated annealing with the computer program X-PLOR, leading to a crystallographic R factor of 0.22 using reflections between 8 and 3 A. The spheroidene molecule which is bound to the Y reaction center has been fitted in the electron density map as a 15-cis isomer with a highly asymmetric structure. The cis-bond is located at proximity from ring 1 of the accessory bacteriochlorophyll on the inactive M side. The nature of the cis-bond was confirmed by resonance Raman spectra obtained from Y reaction center crystals. The structure of spheroidene in Y reaction center is compared to that proposed for 1,2-dihydroneurosporene in Rhodopseudomonas viridis reaction center crystals.
利用无类胡萝卜素突变体球形红细菌R26反应中心的原子坐标，已在3埃分辨率下解析出球形红细菌Y反应中心的结构。该结构通过使用计算机程序X-PLOR进行模拟退火精修，利用8至3埃之间的反射，得到的晶体学R因子为0.22。与Y反应中心结合的球形烯分子在电子密度图中被拟合为具有高度不对称结构的15-顺式异构体。顺式键位于非活性M侧辅助细菌叶绿素环1附近。通过从Y反应中心晶体获得的共振拉曼光谱证实了顺式键的性质。将Y反应中心中球形烯的结构与绿假单胞菌反应中心晶体中1,2-二氢神经孢烯的结构进行了比较。
