Biomaterial Database

Coupling of quinone dynamics to proton pumping in respiratory complex I. 2020

Outi Haapanen, and Marco Reidelbach, and Vivek Sharma

Department of Physics, University of Helsinki, Finland.

Respiratory complex I (NADH:quinone oxidoreductase) plays a central role in generating the proton electrochemical gradient in mitochondrial and bacterial membranes, which is needed to generate ATP. Several high-resolution structures of complex I have been determined, revealing its intricate architecture and complementing the biochemical and biophysical studies. However, the molecular mechanism of long-range coupling between ubiquinone (Q) reduction and proton pumping is not known. Computer simulations have been applied to decipher the dynamics of Q molecule in the ~30 Å long Q tunnel. In this short report, we discuss the binding and dynamics of Q at computationally predicted Q binding sites, many of which are supported by structural data on complex I. We suggest that the binding of Q at these sites is coupled to proton pumping by means of conformational rearrangements in the conserved loops of core subunits.

UI	MeSH Term	Description	Entries
D008055	Lipids	A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)	Lipid
D008968	Molecular Conformation	The characteristic three-dimensional shape of a molecule.	Molecular Configuration,3D Molecular Structure,Configuration, Molecular,Molecular Structure, Three Dimensional,Three Dimensional Molecular Structure,3D Molecular Structures,Configurations, Molecular,Conformation, Molecular,Conformations, Molecular,Molecular Configurations,Molecular Conformations,Molecular Structure, 3D,Molecular Structures, 3D,Structure, 3D Molecular,Structures, 3D Molecular
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D016227	Benzoquinones	Benzene rings which contain two ketone moieties in any position. They can be substituted in any position except at the ketone groups.	1,2-Benzoquinones,1,4-Benzoquinones,Benzodiones,2,5-Cyclohexadiene-1,4-Diones,o-Benzoquinones,p-Benzoquinones
D017494	Proton Pumps	Integral membrane proteins that transport protons across a membrane. This transport can be linked to the hydrolysis of ADENOSINE TRIPHOSPHATE. What is referred to as proton pump inhibitors frequently is about POTASSIUM HYDROGEN ATPASE.	H(+) Pump,H+ Pump,Proton Pump,Pump, H+,Pump, Proton,Pumps, Proton
D042967	Electron Transport Complex I	A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.	NADH Dehydrogenase (Ubiquinone),Complex I Dehydrogenase,NADH DH I,NADH Dehydrogenase Complex 1,NADH Dehydrogenase I,NADH Q1 Oxidoreductase,NADH-CoQ Reductase,NADH-Coenzyme Q Reductase,NADH-Ubiquinone Oxidoreductase,NADH-Ubiquinone Reductase,Respiratory Complex I,Rotenone-Sensitive Mitochondrial NADH-Ubiquinone Oxidoreductase,Ubiquinone Reductase,Dehydrogenase, Complex I,NADH CoQ Reductase,NADH Coenzyme Q Reductase,NADH Ubiquinone Oxidoreductase,NADH Ubiquinone Reductase,Oxidoreductase, NADH Q1,Oxidoreductase, NADH-Ubiquinone,Reductase, NADH-Ubiquinone,Rotenone Sensitive Mitochondrial NADH Ubiquinone Oxidoreductase