4XTL image
Deposition Date 2015-01-23
Release Date 2015-04-01
Last Version Date 2024-01-10
Entry Detail
PDB ID:
4XTL
Title:
Crystal structure of the light-driven sodium pump KR2 in the monomeric blue form, pH 4.3
Biological Source:
Source Organism:
Host Organism:
Method Details:
Experimental Method:
Resolution:
1.45 Å
R-Value Free:
0.21
R-Value Work:
0.18
R-Value Observed:
0.18
Space Group:
I 2 2 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Sodium pumping rhodopsin
Gene (Uniprot):NaR
Chain IDs:A
Chain Length:288
Number of Molecules:1
Biological Source:Dokdonia eikasta
Modified Residue
Compound ID Chain ID Parent Comp ID Details 2D Image
LYR A LYS modified residue
Primary Citation
Crystal structure of a light-driven sodium pump.
Nat.Struct.Mol.Biol. 22 390 395 (2015)
PMID: 25849142 DOI: 10.1038/nsmb.3002

Abstact

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.

Legend

Protein

Chemical

Disease

Primary Citation of related structures