| description | Protein which interacts with quinones. Quinones are aromatic dicarbonyl compounds, where the two carbonyl groups are usually in the para position. Most naturally occuring quinones contain a long isoprenoid side chain, and are divided in two major structural groups, the naphtoquinones and benzoquinones; the number of isoprene units depends on the organism. These highly hydrophobic molecules are mainly involved in electron transport, as electron carriers in redox reactions. For example, ubiquinone (coenzyme Q) and menaquinone (vitamin K2) are essential components of the respiratory electron transport chain. Plastoquinone, found in chloroplasts and in cyanobacteria, functions as one of the carrier molecules of the electron transport chain in photosynthesis. Phylloquinone (vitamin K1) is the major form of vitamin K found in plants. Chlorobiumquinone, demethylmenaquinone, alpha-tocopherolquinone, rhodoquinone, epoxyubiquinone and caldariellaquinone are other quinones found in several species |
