2.4-Å structure of the double-ring Gemmatimonas phototrophica photosystem

Pu Qian, Alastair T Gardiner, Ivana Šímová, Katerina Naydenova, Tristan I Croll, Philip J Jackson, Nupur, Miroslav Kloz, Petra Čubáková, Marek Kuzma, Yonghui Zeng, Pablo Castro-Hartmann, Bart van Knippenberg, Kenneth N Goldie, David Kaftan, Pavel Hrouzek, Jan Hájek, Jon Agirre, C Alistair Siebert, David BínaKasim Sader, Henning Stahlberg, Roman Sobotka, Christopher J Russo, Tomáš Polívka, C Neil Hunter, Michal Koblížek

Research output: Contribution to journalArticlepeer-review

Abstract

Phototrophic Gemmatimonadetes evolved the ability to use solar energy following horizontal transfer of photosynthesis-related genes from an ancient phototrophic proteobacterium. The electron cryo-microscopy structure of the Gemmatimonas phototrophica photosystem at 2.4 Å reveals a unique, double-ring complex. Two unique membrane-extrinsic polypeptides, RC-S and RC-U, hold the central type 2 reaction center (RC) within an inner 16-subunit light-harvesting 1 (LH1) ring, which is encircled by an outer 24-subunit antenna ring (LHh) that adds light-gathering capacity. Femtosecond kinetics reveal the flow of energy within the RC-dLH complex, from the outer LHh ring to LH1 and then to the RC. This structural and functional study shows that G. phototrophica has independently evolved its own compact, robust, and highly effective architecture for harvesting and trapping solar energy.

Original languageEnglish
Article numbereabk3139
Number of pages11
JournalScience Advances
Volume8
Issue number7
DOIs
Publication statusPublished - 16 Feb 2022

Bibliographical note

© 2022 The Authors

Cite this