9OXL
SthK closed state at low temperature, cAMP-bound in the presence of DOPE
Summary for 9OXL
| Entry DOI | 10.2210/pdb9oxl/pdb |
| EMDB information | 70988 |
| Descriptor | Transcriptional regulator, Crp/Fnr family, ADENOSINE-3',5'-CYCLIC-MONOPHOSPHATE, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (3 entities in total) |
| Functional Keywords | cyclic nucleotide-gated channel, lipid modulation, pacemaker channel, transport protein, potassium channel, thermoreceptor |
| Biological source | Spirochaeta thermophila |
| Total number of polymer chains | 4 |
| Total formula weight | 226624.07 |
| Authors | |
| Primary citation | Li, C.C.,Nimigean, C.M. Mechanism of lipid-dependent cold sensitivity in a model ion channel. Nat Commun, 2026 Cited by PubMed Abstract: Temperature sensing enables organisms to detect and respond to environmental changes. While temperature-responsive ion channels are key to this process, the physico-chemical mechanisms by which they sense temperature remain poorly understood. Here, we investigate the molecular details of temperature sensing in the model bacterial channel, SthK from Spirochaeta thermophila. We show that SthK is cold sensitive, displaying higher activity below 30 °C. Remarkably, SthK cold sensitivity depends strongly on membrane lipids, being sensitive in amine-containing lipids but insensitive in anionic lipids. Combining cryo-EM structural analysis, mutagenesis, and functional assays, we identify an intersubunit salt bridge that acts as temperature sensor. This salt bridge forms only in closed states, and determines channel opening by controlling closed-state stability. Lower temperatures weaken salt-bridge interactions, favoring channel opening, and lipid headgroups tune temperature sensitivity by modulating salt-bridge strength. These findings highlight how thermosensitivity can emerge from cooperative interactions between protein and the surrounding membrane. PubMed: 41963351DOI: 10.1038/s41467-026-71714-3 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.62 Å) |
Structure validation
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