3X3C

Crystal structure of the light-driven sodium pump KR2 in neutral state

Summary for 3X3C

• Entry DOI: 10.2210/pdb3x3c/pdb
• Related: 3X3B
• Descriptor: Sodium pumping rhodopsin, RETINAL, OLEIC ACID, ... (4 entities in total)
• Functional Keywords: membrane protein, light-driven sodium pump
• Biological source: Dokdonia eikasta
• Total number of polymer chains: 1
• Total formula weight: 34026.68

Authors

Kato, H.E.,Inoue, K.,Abe-Yoshizumi, R.,Kato, Y.,Ono, H.,Konno, M.,Ishizuka, T.,Hoque, M.R.,Hososhima, S.,Kunitomo, H.,Ito, J.,Yoshizawa, S.,Yamashita, K.,Takemoto, M.,Nishizawa, T.,Taniguchi, R.,Kogure, K.,Maturana, A.D.,Iino, Y.,Yawo, H.,Ishitani, R.,Kandori, H.,Nureki, O. (deposition date: 2015-01-18, release date: 2015-04-08, Last modification date: 2024-03-20)

Primary citation

Kato, H.E.,Inoue, K.,Abe-Yoshizumi, R.,Kato, Y.,Ono, H.,Konno, M.,Hososhima, S.,Ishizuka, T.,Hoque, M.R.,Kunitomo, H.,Ito, J.,Yoshizawa, S.,Yamashita, K.,Takemoto, M.,Nishizawa, T.,Taniguchi, R.,Kogure, K.,Maturana, A.D.,Iino, Y.,Yawo, H.,Ishitani, R.,Kandori, H.,Nureki, O.
Structural basis for Na(+) transport mechanism by a light-driven Na(+) pump
Nature, 521:48-53, 2015

PubMed Abstract: Krokinobacter eikastus rhodopsin 2 (KR2) is the first light-driven Na(+) pump discovered, and is viewed as a potential next-generation optogenetics tool. Since the positively charged Schiff base proton, located within the ion-conducting pathway of all light-driven ion pumps, was thought to prohibit the transport of a non-proton cation, the discovery of KR2 raised the question of how it achieves Na(+) transport. Here we present crystal structures of KR2 under neutral and acidic conditions, which represent the resting and M-like intermediate states, respectively. Structural and spectroscopic analyses revealed the gating mechanism, whereby the flipping of Asp116 sequesters the Schiff base proton from the conducting pathway to facilitate Na(+) transport. Together with the structure-based engineering of the first light-driven K(+) pumps, electrophysiological assays in mammalian neurons and behavioural assays in a nematode, our studies reveal the molecular basis for light-driven non-proton cation pumps and thus provide a framework that may advance the development of next-generation optogenetics.

PubMed: 25849775
DOI: 10.1038/nature14322

Experimental method

X-RAY DIFFRACTION (2.3 Å)