The enzyme participates in folate (in bacteria, plants and fungi) and methanopterin (in archaea) biosynthesis. The enzymes from the bacterium?Escherichia coli?and the plant?Arabidopsis thaliana?also catalyse the epimerisation of the 2′ hydroxy-group (EC?5.1.99.8, 7,8-dihydroneopterin epimerase) [2,3]. The enzyme from the bacterium?Mycobacterium tuberculosis?is trifunctional and also catalyses EC?5.1.99.8, and EC?1.13.11.81, 7,8-dihydroneopterin oxygenase [6]. The enzyme from the yeast?Saccharomyces cerevisiae?also catalyses the two subsequent steps in the folate biosynthesis pathway – EC?2.7.6.3, 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase, and EC?2.5.1.15, dihydropteroate synthase [4].
