4U9S

Crystal structure of NqrC from Vibrio cholerae

Summary for 4U9S

• Entry DOI: 10.2210/pdb4u9s/pdb
• Related: 4P6V
• Descriptor: Na(+)-translocating NADH-quinone reductase subunit C, FLAVIN MONONUCLEOTIDE, GLYCEROL, ... (5 entities in total)
• Functional Keywords: sodium translocation, oxidoreductase
• Biological source: Vibrio cholerae
• Cellular location: Cell inner membrane ; Single-pass membrane protein : A5F5Y7
• Total number of polymer chains: 1
• Total formula weight: 24352.95

Authors

Fritz, G. (deposition date: 2014-08-06, release date: 2014-12-03, Last modification date: 2024-11-13)

Primary citation

Steuber, J.,Vohl, G.,Casutt, M.S.,Vorburger, T.,Diederichs, K.,Fritz, G.
Structure of the V. cholerae Na+-pumping NADH:quinone oxidoreductase.
Nature, 516:62-67, 2014

PubMed Abstract: NADH oxidation in the respiratory chain is coupled to ion translocation across the membrane to build up an electrochemical gradient. The sodium-translocating NADH:quinone oxidoreductase (Na(+)-NQR), a membrane protein complex widespread among pathogenic bacteria, consists of six subunits, NqrA, B, C, D, E and F. To our knowledge, no structural information on the Na(+)-NQR complex has been available until now. Here we present the crystal structure of the Na(+)-NQR complex at 3.5 Å resolution. The arrangement of cofactors both at the cytoplasmic and the periplasmic side of the complex, together with a hitherto unknown iron centre in the midst of the membrane-embedded part, reveals an electron transfer pathway from the NADH-oxidizing cytoplasmic NqrF subunit across the membrane to the periplasmic NqrC, and back to the quinone reduction site on NqrA located in the cytoplasm. A sodium channel was localized in subunit NqrB, which represents the largest membrane subunit of the Na(+)-NQR and is structurally related to urea and ammonia transporters. On the basis of the structure we propose a mechanism of redox-driven Na(+) translocation where the change in redox state of the flavin mononucleotide cofactor in NqrB triggers the transport of Na(+) through the observed channel.

PubMed: 25471880
DOI: 10.1038/nature14003

Experimental method

X-RAY DIFFRACTION (1.7 Å)