TY - JOUR A1 - Kriebel, Clara Nassrin A1 - Asido, Marvin A1 - Kaur, Jagdeep A1 - Orth, Jennifer A1 - Braun, Philipp A1 - Becker-Baldus, Johanna A1 - Wachtveitl, Josef A1 - Glaubitz, Clemens T1 - Structural and functional consequences of the H180A mutation of the light-driven sodium pump KR2 T2 - Biophysical Journal N2 - Krokinobacter eikastus rhodopsin 2 (KR2) is a light-driven pentameric sodium pump. Its ability to translocate cations other than protons and to create an electrochemical potential makes it an attractive optogenetic tool. Tailoring its ion pumping characteristics by mutations is therefore of great interest. In addition, understanding the functional and structural consequences of certain mutations helps to derive a functional mechanism of ion selectivity and transfer of KR2. Based on solid-state NMR spectroscopy, we report an extensive chemical shift resonance assignment of KR2 within lipid bilayers. This data set was then used to probe site-resolved allosteric effects of sodium binding, which revealed multiple responsive sites including the Schiff base nitrogen and the NDQ motif. Based on this data set, the consequences of the H180A mutation are probed. The mutant is silenced in the presence of sodium while in its absence, proton pumping is observed. Our data reveal specific long-range effects along the sodium transfer pathway. These experiments are complemented by time-resolved optical spectroscopy. Our data suggest a model in which sodium uptake by the mutant can still take place, while sodium release and backflow control are disturbed. Y1 - 2022 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62893 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-628930 UR - https://www.uni-frankfurt.de/130058336/Kriebel_Glaubitz_Biophys_J_2022_AAM.pdf N1 - This work was funded by DFG/SFB807 “Transport and communications across membranes” and DFG grant 391643887. N1 - This is an Accepted Manuscript version of the following article, accepted for publication in Biophysical Journal: Clara Nassrin Kriebel, Marvin Asido, Jagdeep Kaur, Jennifer Orth, Philipp Braun, Johanna Becker-Baldus, Josef Wachtveitl, and Clemens Glaubitz (2022): „Structural and Functional Consequences of the H180A Mutation of the Light-Driven Sodium Pump KR2“. Biophysical Journal. https://doi.org/10.1016/j.bpj.2022.12.023. © 2022. VL - 2022 IS - Accepted manuscript version ER -