6tk1

Femtosecond to millisecond structural changes in a light-driven sodium pump: 20ms structure of KR2 with extrapolated, light and dark datasets

spinqualitylabelsall models 6tk1, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6tk1 is a 1 chain structure with sequence from Dokdonia eikasta. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: LFA, NA, RET Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function N0DKS8_9FLAO Publication Abstract from PubMed Light-driven sodium pumps actively transport small cations across cellular membranes(1). These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved(2,3), it is unclear how structural alterations over time allow sodium to be translocated against a concentration gradient. Here, using the Swiss X-ray Free Electron Laser(4), we have collected serial crystallographic data at ten pump-probe delays from femtoseconds to milliseconds. High-resolution structural snapshots throughout the KR2 photocycle show how retinal isomerization is completed on the femtosecond timescale and changes the local structure of the binding pocket in the early nanoseconds. Subsequent rearrangements and deprotonation of the retinal Schiff base open an electrostatic gate in microseconds. Structural and spectroscopic data, in combination with quantum chemical calculations, indicate that a sodium ion binds transiently close to the retinal within one millisecond. In the last structural intermediate, at 20 milliseconds after activation, we identified a potential second sodium-binding site close to the extracellular exit. These results provide direct molecular insight into the dynamics of active cation transport across biological membranes. Femtosecond-to-millisecond structural changes in a light-driven sodium pump.,Skopintsev P, Ehrenberg D, Weinert T, James D, Kar RK, Johnson PJM, Ozerov D, Furrer A, Martiel I, Dworkowski F, Nass K, Knopp G, Cirelli C, Arrell C, Gashi D, Mous S, Wranik M, Gruhl T, Kekilli D, Brunle S, Deupi X, Schertler GFX, Benoit RM, Panneels V, Nogly P, Schapiro I, Milne C, Heberle J, Standfuss J Nature. 2020 May 20. pii: 10.1038/s41586-020-2307-8. doi:, 10.1038/s41586-020-2307-8. PMID:32499654 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Rhodopsin 3D structures

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