Klyszejko Adriana L, Shastri Sarika, Mari Stefania A, Grubmüller Helmut, Muller Daniel J, Glaubitz Clemens
Biotechnology Center, University of Technology Dresden, Germany.
J Mol Biol. 2008 Feb 8;376(1):35-41. doi: 10.1016/j.jmb.2007.11.030. Epub 2007 Nov 19.
Proteorhodopsins (PRs), the recently discovered light-driven proton pumps, play a major role in supplying energy for microbial organisms of oceans. In contrast to PR, rhodopsins found in Archaea and Eukarya are structurally well characterized. Using single-molecule microscopy and spectroscopy, we observed the oligomeric assembly of native PR molecules and detected their folding in the membrane. PR showed unfolding patterns identical with those of bacteriorhodopsin and halorhodopsin, indicating that PR folds similarly to archaeal rhodopsins. Surprisingly, PR predominantly assembles into hexameric oligomers, with a smaller fraction assembling into pentamers. Within these oligomers, PR arranged into radial assemblies. We suggest that this structural assembly of PR may have functional implications.
视紫质（PRs）是最近发现的光驱动质子泵，在为海洋微生物提供能量方面发挥着重要作用。与PR不同，古细菌和真核生物中发现的视紫红质在结构上有很好的特征描述。利用单分子显微镜和光谱学，我们观察了天然PR分子的寡聚组装，并检测到它们在膜中的折叠。PR显示出与细菌视紫红质和卤视紫红质相同的解折叠模式，表明PR的折叠方式与古细菌视紫红质相似。令人惊讶的是，PR主要组装成六聚体寡聚体，只有一小部分组装成五聚体。在这些寡聚体内，PR排列成放射状组装。我们认为PR的这种结构组装可能具有功能意义。
