Abstract
AbstractIndoleamine 2,3‐dioxygenase (IDO) and tryptophan 2,3‐dioxygenase (TDO) are heme‐containing enzymes from a small family of homologous enzymes. Despite both catalyzing the dioxygenation ofL‐tryptophan, the first step in the kynurenine pathway, the sequence similarity between TDO and IDO is low. Alignment of sequences across this family of enzymes is only possible on the basis of their structures. Human IDO shows activity toward a wider range of substrates than TDO, and is found throughout the body, while TDO is limited to the liver and epidermis in mammals. To date, no functional prokaryotic IDO has been identified, while TDO is found in many bacteria. TDO and IDO have been implicated in a number of human physiological conditions, including suppression of T‐cell proliferation and the immune escape of cancers, making them attractive targets for drug discovery.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
