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Updated: Jun 17, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Atomic structure of the bacteriochlorophyll c assembly in intact chlorosomes from Chlorobium limicola determined by
Hideo Akutsu1, Ayako Egawa, Toshimichi Fujiwara
1Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Japan. akutsu@protein.osaka-u.ac.jp
Abstract:
Green sulfur photosynthetic bacteria optimize their antennas, chlorosomes, especially for harvesting weak light by organizing bacteriochlorophyll (BChl) assembly without any support of proteins. As it is difficult to crystallize the organelles, a high-resolution structure of the light-harvesting devices in the chlorosomes has not been clarified. We have determined the structure of BChl c assembly in the intact chlorosomes from Chlorobium limicola on the basis of (13)C dipolar spin-diffusion solid-state NMR analysis of uniformly (13)C-labeled chlorosomes. About 90 intermolecular C-C distances were obtained by the simultaneous assignment of distance correlations and the structure optimization preceded by the polarization-transfer matrix analysis. An atomic structure was obtained, using these distance constraints. The determined structure of the chlorosomal BChl c assembly is built with the parallel layers of piggyback-dimers. This supramolecular structure would provide insights into the mechanism of weak-light capturing.
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