CoQ Cytochrome c reductase

The Coenzyme Q - cytochrome c reductase complex, sometimes called the cytochrome bc₁ complex, and at other times Complex III, is the third complex in the electron transfer chain (PDB 1KYO, EC 1.10.2.2). It is a transmembrane lipoprotein, and it catalyzes the reduction of cytochrome c by accepting reducing equivalents from Coenzyme Q (CoQ): Image File history File links Gen w/ Deepview from PDB:1KYO File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Gen w/ Deepview from PDB:1KYO File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The electron transfer chain (also called the electron transport chain, ETC, e-train, or simply electron transport), is any series of protein complexes and lipid-soluble messengers that convert the reductive potential of energized electrons into a cross-membrane proton gradient. ... The Protein Data Bank (PDB) is a repository for 3-D structural data of proteins and nucleic acids. ... EC numbers (Enzyme Commission numbers) are a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ... A lipoprotein is a biochemical assembly that contains both proteins and lipids and may be structural or catalytic in function. ... Cytochrome c (horse heart: PDB 1HRC) is a small heme protein found loosely associated with the inner membrane of the mitochondrion. ... Coenzyme Q (CoQ), also known as ubiquinone or ubiquinol, is a biologically active quinone with an isoprenoid side chain, related in structure to vitamin K and vitamin E. // History Coenzyme Q was first discovered in 1957 by professor F. L. Crane and colleagues at the University of Wisconsin Enzyme Institute. ...

CoQH₂+ 2 Fe⁺³-cytochrome c → CoQ + 2 Fe⁺²-cytochrome c

In the process, protons are translocated across the mitochondrial membrane. Therefore, the bc₁ complex is a proton pump. Mitochondria structure : 1) Inner membrane 2) Outer membrane 3) Crista 4) Matrix In cell biology, a mitochondrion (plural mitochondria) (from Greek mitos thread + khondrion granule) is an organelle found in most eukaryotic cells. ... A biological membrane or biomembrane is a membrane which acts as a barrier within or around a cell. ... A proton pump is an integral membrane protein that is capable of moving protons across the membrane of a cell, mitochondrion, or other subcellular compartment, thereby creating a difference or gradient in both pH and electrical charge (ignoring differences in buffer capacity) and tending to establish an electrochemical potential. ...

Compared to the other major proton pumping subunits of the electron transport chain, the number of subunits found can be small, as small as three polypeptide chains. This number does increase, and as many as eleven subunits can be found in higher animals. The major prosthetic groups in the complex are a pair of cytochromes, the b cytochrome and the c₁ cytochrome, and a two iron, two sulfur iron-sulfur cluster. The electron transfer chain (also called the electron transport chain, ETC, e-train, or simply electron transport), is any series of protein complexes and lipid-soluble messengers that convert the reductive potential of energized electrons into a cross-membrane proton gradient. ... A coenzyme (a. ... Cytochromes are generally membrane-bound proteins that contain heme groups and carry out electron transport or catalyse reductive/oxidative reactions. ... Cytochromes are generally membrane-bound proteins that contain heme groups and carry out electron transport or catalyse reductive/oxidative reactions. ... Cytochromes are generally membrane-bound proteins that contain heme groups and carry out electron transport or catalyse reductive/oxidative reactions. ... An iron-sulfur cluster is a structural motif found in certain metalloproteins, such as the ferredoxins, as well as NADH dehydrogenase and Coenzyme Q - cytochrome c reductase of the electron transfer system. ...

The toxic antimycin-A inhibits the transfer of electrons from Complex III to Complex IV (Cytochrome c oxidase). Antimycin is an antibiotic which inhibits the electron transport chain between cytochrome B and cytochrome C Categories: Biochemistry stubs | Antibiotics ... Cytochrome c oxidase The enzyme cytochrome c oxidase (PDB 2OCC, EC 1. ...

See also

• Cellular respiration
• Photosynthetic reaction centre

Cellular respiration is the process in which the chemical bonds of energy-rich molecules such as glucose are converted into energy usable for life processes. ... An electron micrograph of a series of reaction centres and light harvesting complexes from the surface of the thylakoid membrane inside a chloroplast. ...

External links

• Cytochrome bc₁ complex page.
• Interactive Molecular model of Coenzyme Q - cytochrome c reductase (Requires MDL Chime)