4XTO

Crystal structure of the light-driven sodium pump KR2 in the pentameric red form, pH 5.6

Summary for 4XTO

• Entry DOI: 10.2210/pdb4xto/pdb
• Descriptor: Sodium pumping rhodopsin, SODIUM ION, EICOSANE, ... (4 entities in total)
• Functional Keywords: ion pump, membrane protein
• Biological source: Dokdonia eikasta
• Total number of polymer chains: 5
• Total formula weight: 167335.46

Authors

Gushchin, I.,Shevchenko, V.,Polovinkin, V.,Gordeliy, V. (deposition date: 2015-01-23, release date: 2015-04-01, Last modification date: 2024-01-10)

Primary citation

Gushchin, I.,Shevchenko, V.,Polovinkin, V.,Kovalev, K.,Alekseev, A.,Round, E.,Borshchevskiy, V.,Balandin, T.,Popov, A.,Gensch, T.,Fahlke, C.,Bamann, C.,Willbold, D.,Buldt, G.,Bamberg, E.,Gordeliy, V.
Crystal structure of a light-driven sodium pump.
Nat.Struct.Mol.Biol., 22:390-395, 2015

PubMed Abstract: Recently, the first known light-driven sodium pumps, from the microbial rhodopsin family, were discovered. We have solved the structure of one of them, Krokinobacter eikastus rhodopsin 2 (KR2), in the monomeric blue state and in two pentameric red states, at resolutions of 1.45 Å and 2.2 and 2.8 Å, respectively. The structures reveal the ion-translocation pathway and show that the sodium ion is bound outside the protein at the oligomerization interface, that the ion-release cavity is capped by a unique N-terminal α-helix and that the ion-uptake cavity is unexpectedly large and open to the surface. Obstruction of the cavity with the mutation G263F imparts KR2 with the ability to pump potassium. These results pave the way for the understanding and rational design of cation pumps with new specific properties valuable for optogenetics.

PubMed: 25849142
DOI: 10.1038/nsmb.3002

Experimental method

X-RAY DIFFRACTION (2.8 Å)