9SOG
Atomic resolution structure of viral channelrhodopsin OLPVR1 in a calcium-blocked state
Summary for 9SOG
| Entry DOI | 10.2210/pdb9sog/pdb |
| Descriptor | rhodopsin, N~6~-[(2Z,4E,6E,8E)-3,7-DIMETHYL-9-(2,6,6-TRIMETHYLCYCLOHEX-1-EN-1-YL)NONA-2,4,6,8-TETRAENYL]LYSINE, rhodopsin, EICOSANE, (2S)-2,3-dihydroxypropyl (9Z)-hexadec-9-enoate, ... (8 entities in total) |
| Functional Keywords | open channel, ca2+, rhodopsin, optogenetics, calcium signalling, membrane protein |
| Biological source | Organic Lake phycodnavirus More |
| Total number of polymer chains | 1 |
| Total formula weight | 35416.96 |
| Authors | Bukhdruker, S.,Zabelskii, D.,Bourenkov, G.,Gordeliy, V. (deposition date: 2025-09-12, release date: 2026-09-23, Last modification date: 2026-09-30) |
| Primary citation | Zabelskii, D.,Bukhdruker, S.,Lamm, G.H.U.,Bukhalovich, S.,Aoyama, M.,Sudarev, V.,Kuzmin, A.,Shibata, M.,Kotayama, K.,Kandori, H.,Wachtveitl, J.,Bamberg, E.,Gordeliy, V. Molecular mechanism of calcium inhibition in viral channelrhodopsins. Nat Commun, 17:-, 2026 Cited by PubMed Abstract: Viral channelrhodopsins (VCR1s) are giant-virus-encoded light-gated channels permeable to monovalent and divalent cations, including Na and Ca ions, and inhibited by millimolar Ca concentrations. Here, we combine X-ray crystallography, time-resolved UV-vis spectroscopy, and ATR-FTIR spectroscopy to investigate molecular mechanisms of ion permeation and Ca-dependent inhibition in OLPVR1. An atomic resolution structure of OLPVR1 obtained in the presence of 10 mM CaCl and 900 mM NaCl reveals a transient intracellular Ca binding site near T87 and T88, close to the retinal cofactor. Upon photoactivation, this Ca ion prevents a key rearrangement of the intracellular gate required for ion translocation, namely the flip of E44, thereby disrupting ion conduction. Instead, illumination leads to the accumulation of Na ions between E44, S208 and the carbonyl oxygen of retinal-binding residue K204. Our findings reveal the molecular basis of Ca-dependent inhibition in VCR1s and provide a foundation for engineering enhanced tools for calcium optogenetics. PubMed: 42749743DOI: 10.1038/s41467-026-77716-5 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.52 Å) |
Structure validation
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