Cytokinin dehydrogenase () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are a cytokinin such as N6-isopentenyladenine, an electron acceptor, and water. Its products are adenine, 3-methyl-2-butenal (or other aldehyde in case of different substrates), and the corresponding reduced acceptor.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with other acceptors. The systematic name of this enzyme class is N<sup>6</sup>-dimethylallyladenine:acceptor oxidoreductase. Other names in common use include N<sup>6</sup>-dimethylallyladenine:(acceptor) oxidoreductase, 6-N-dimethylallyladenine:acceptor oxidoreductase, and cytokinin oxidase/dehydrogenase abbreviated as CKX.
As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes , , , , , and . , there have been 18 structures recorded.