6GYH

Crystal structure of the light-driven proton pump Coccomyxa subellipsoidea Rhodopsin CsR

Summary for 6GYH

• Entry DOI: 10.2210/pdb6gyh/pdb
• Descriptor: Family A G protein-coupled receptor-like protein, RETINAL, CHOLESTEROL, ... (5 entities in total)
• Functional Keywords: retinal, microbial-type rhodopsin, light-driven proton pump, seven trans-membrane, transport protein, proton transport, membrane protein
• Biological source: Coccomyxa subellipsoidea C-169 (Green microalga)
• Total number of polymer chains: 1
• Total formula weight: 27830.34

Authors

Szczepek, M.,Schmidt, A.,Scheerer, P. (deposition date: 2018-06-29, release date: 2019-03-27, Last modification date: 2024-01-17)

Primary citation

Fudim, R.,Szczepek, M.,Vierock, J.,Vogt, A.,Schmidt, A.,Kleinau, G.,Fischer, P.,Bartl, F.,Scheerer, P.,Hegemann, P.
Design of a light-gated proton channel based on the crystal structure ofCoccomyxarhodopsin.
Sci.Signal., 12:-, 2019

PubMed Abstract: The light-driven proton pump rhodopsin (CsR) provides-because of its high expression in heterologous host cells-an opportunity to study active proton transport under controlled electrochemical conditions. In this study, solving crystal structure of CsR at 2.0-Å resolution enabled us to identify distinct features of the membrane protein that determine ion transport directivity and voltage sensitivity. A specific hydrogen bond between the highly conserved Arg and the nearby nonconserved tyrosine (Tyr) guided our structure-based transformation of CsR into an operational light-gated proton channel (CySeR) that could potentially be used in optogenetic assays. Time-resolved electrophysiological and spectroscopic measurements distinguished pump currents from channel currents in a single protein and emphasized the necessity of Arg mobility in CsR as a dynamic extracellular barrier to prevent passive conductance. Our findings reveal that molecular constraints that distinguish pump from channel currents are structurally more confined than was generally expected. This knowledge might enable the structure-based design of novel optogenetic tools, which derive from microbial pumps and are therefore ion specific.

PubMed: 30890657
DOI: 10.1126/scisignal.aav4203

Experimental method

X-RAY DIFFRACTION (2 Å)