Rhodopsin-bestrophin fusion proteins from unicellular algae form gigantic pentameric ion channels

Andrey Rozenberg, Igor Kaczmarczyk, Donna Matzov, Johannes Vierock, Takashi Nagata, Masahiro Sugiura, Kota Katayama, Yuma Kawasaki, Masae Konno, Yujiro Nagasaka, Mako Aoyama, Ishita Das, Efrat Pahima, Jonathan Church, Suliman Adam, Veniamin A. Borin, Ariel Chazan, Sandra Augustin, Jonas Wietek, Julien DineYoav Peleg, Akira Kawanabe, Yuichiro Fujiwara, Ofer Yizhar, Mordechai Sheves, Igor Schapiro, Yuji Furutani, Hideki Kandori, Keiichi Inoue, Peter Hegemann, Oded Béjà*, Moran Shalev-Benami*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Many organisms sense light using rhodopsins, photoreceptive proteins containing a retinal chromophore. Here we report the discovery, structure and biophysical characterization of bestrhodopsins, a microbial rhodopsin subfamily from marine unicellular algae, in which one rhodopsin domain of eight transmembrane helices or, more often, two such domains in tandem, are C-terminally fused to a bestrophin channel. Cryo-EM analysis of a rhodopsin-rhodopsin-bestrophin fusion revealed that it forms a pentameric megacomplex (~700 kDa) with five rhodopsin pseudodimers surrounding the channel in the center. Bestrhodopsins are metastable and undergo photoconversion between red- and green-absorbing or green- and UVA-absorbing forms in the different variants. The retinal chromophore, in a unique binding pocket, photoisomerizes from all-trans to 11-cis form. Heterologously expressed bestrhodopsin behaves as a light-modulated anion channel.

Original languageAmerican English
Pages (from-to)592-603
Number of pages12
JournalNature Structural and Molecular Biology
Issue number6
StatePublished - Jun 2022

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© 2022, The Author(s), under exclusive licence to Springer Nature America, Inc.


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