TY  - INPR
A1  - Podoliak, Elizaveta
A1  - Lamm, Gerrit H. U.
A1  - Alekseev, Alexey
A1  - Marin, Egor
A1  - Schellbach, Anna V.
A1  - Fedotov, Daniil A.
A1  - Stetsenko, Artem
A1  - Maliar, Nina
A1  - Bourenkov, Gleb
A1  - Balandin, Taras
A1  - Baeken, Christian
A1  - Astashkin, Roman
A1  - Schneider, Thomas R.
A1  - Bateman, Alex
A1  - Wachtveitl, Josef
A1  - Schapiro, Igor
A1  - Busskamp, Volker
A1  - Guskov, Albert
A1  - Gordeliy, Valentin
A1  - Kovalev, Kirill
T1  - A novel subgroup of light-driven sodium pumps with an additional Schiff base counterion
T2  - bioRxiv
N2  - Light-driven sodium pumps (NaRs) are unique ion-transporting microbial rhodopsins. The major group of NaRs is characterized by an NDQ motif and has two aspartic acid residues in the central region essential for sodium transport. Here we identified a new subgroup of the NDQ rhodopsins bearing an additional glutamic acid residue in the close vicinity to the retinal Schiff base. We thoroughly characterized a member of this subgroup, namely the protein ErNaR from Erythrobacter sp. HL-111 and showed that the additional glutamic acid results in almost complete loss of pH sensitivity for sodium-pumping activity, which is in contrast to previously studied NaRs. ErNaR is capable of transporting sodium efficiently even at acidic pH levels. X-ray crystallography and single particle cryo-electron microscopy reveal that the additional glutamic acid residue mediates the connection between the other two Schiff base counterions and strongly interacts with the aspartic acid of the characteristic NDQ motif. Hence, it reduces its pKa. Our findings shed light on a new subgroup of NaRs and might serve as a basis for their rational optimization for optogenetics.
Y1  - 2023
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/79455
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-794557
UR  - https://www.biorxiv.org/content/10.1101/2023.10.11.561842v1
IS  - 2023.10.11.561842 Version 1
PB  - bioRxiv
ER  -