Structural and functional investigations of novel microbial rhodopsins

Microbial rhodopsins constitute a large and diverse superfamily of light-sensitive membrane proteins. They play a major role in solar energy capture in the sea, utilizing it to perform ion translocation, sensory, enzymatic, and other activities. Microbial rhodopsins also found essential applications in medicine in neuroscience, being the core of optogenetics - biotechnology for optical control on living cells and tissues. Our group studies the functional and structural properties of new families of rhodopsins. Recently, we reported the first high-resolution insights into the heliorhodopsin family (1), which showed that these proteins are likely unique photoenzymes with unusual architecture. Next, we determined the structural basis of light-driven sodium pumping by solving the structure of KR2 rhodopsin in its active state (2). Finally, we characterized two members of viral rhodopsins group 1 (3). We showed that they are light-gated Na+/K+-selective channels, inhibited by Ca2+. We also solved a structure of one of them at 1.4 Å. Thus, our studies revealed both functional and mechanistic features of the distinct clades of microbial rhodopsins but also created a strong fundament for further investigations of the expanding superfamily.

(1) High Resolution Structural Insights into the Heliorhodopsin Family. Kovalev K., Volkov D, Astashkin R, Alekseev A, Gushchin I, Haro-Moreno JM, Rogachev A, Balandin T, Borshchevskiy V, Popov A, Bourenkov G, Bamberg E, Rodriguez-Valera F, Bueldt G, Gordeliy V. Nature Communications 2020 Feb 25 ;11:2137.

(2) Molecular mechanism of light-driven sodium pumping. Kovalev K, Astashkin R, Gushchin I, Orekhov P, Volkov D, Zinovev E, Marin E, Rulev M, Alekseev A, Royant A, Carpentier P, Vaganova S, Zabelskii D, Baeken C, Sergeev I, Balandin T, Bourenkov G, Carpena X, Boer R, Maliar N, Borshchevskiy V, Bueldt G, Bamberg E, Gordeliy V. Nature Communications 2020 May 1 ; 11:2137.

(3) Viral Rhodopsins 1 : A Unique Family of Light-Gated Ion Channels. Zabelskii D, Alekseev A, Kovalev K, Rankovic V, Balandin T, Soloviov D, Bratanov D, Savelyeva E, Podolyak E, Volkov D, Vaganova S, Astashkin R, Chizhov I, Yutin N, Rulev M, Popov A, Eria-Oliveira AS, Rokitskaya T, Mager T, Antonenko Y, Rosselli R, Armeev G, Shaitan K, Vivaudou M, Büldt G, Rodriguez-Valera F, Kirpichnikov M, Moser T, Koonin E, Offenhäusser A, Bamberg E, Gordeliy V. Nature Communications 2020 Nov 11 2020 ;11(1):5707.

Contact : Valentin Gordeliy