A calcium-binding protein is a regulatory subunit of quinate:NAD+ oxidoreductase from dark-grown carrot cells.
On transfer of carrot cell-suspensions from light to dark conditions, quinate:NAD+ oxidoreductase binds, post-translationally, an additional subunit. As a consequence, the oligomeric enzyme becomes activatable by Ca++ and behaves as a Ca++ binding protein. The additional subunit has been shown to be the Ca++ binding moiety of the molecule that protects the phosphorylated amino acids from dephosphorylation. It is suggested that the regulatory subunit may be a new class of calciprotein.
D000429:Alcohol Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002478:Cells, Cultured; D003624:Darkness; D007700:Kinetics; D046911:Macromolecular Substances; D010766:Phosphorylation; D010944:Plants / Q000201:enzymology*
D002135:Calcium-Binding Proteins; D046911:Macromolecular Substances; D000429:Alcohol Oxidoreductases; C022511:quinate dehydrogenase; D002118:Calcium