Structure and properties of pyruvate decarboxylase and site-directed mutagenesis of the Zymomonas mobilis enzyme

Pyruvate decarboxylase (EC 4.1.1.1) is a thiamin diphosphate-dependent enzyme that catalyzes the penultimate step in alcohol fermentation. The enzyme is widely distributed in plants and fungi but is rare in prokaryotes and absent in animals. Here we review its structure and properties with particular emphasis on how site-directed mutagenesis of the enzyme from Zymomonas mobilis has assisted us to understand the function of critical residues.