The enzyme tryptophanase () catalyzes the chemical reaction
This enzyme belongs to the family of lyases, specifically in the "catch-all" class of carbon-carbon lyases. The systematic name of this enzyme class is <small>L</small>-tryptophan indole-lyase (deaminating; pyruvate-forming). Other names in common use include <small>L</small>-tryptophanase, and <small>L</small>-tryptophan indole-lyase (deaminating). This enzyme participates in tryptophan metabolism and nitrogen metabolism. It has 2 cofactors: pyridoxal phosphate, and potassium.
As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes 1AX4, 2C44, and 2OQX.