Binds 2 Mg2+ ions that are essential for activity [4]. The enzyme participates in the biosynthetic pathways for folate (in bacteria, plants, fungi, and some archaeal species, including the haloarchaea) and methanopterin (in some archaeal species such as the Archaeoglobi and Methanobacteria). The enzyme exists in varying types of multifunctional proteins in different organisms. The enzyme from the bacterium Streptococcus pneumoniae also harbours the activity of EC
4.1.2.25, dihydroneopterin aldolase [4], the enzyme from the plant Arabidopsis thaliana harbours the activity of EC
2.5.1.15, dihydropteroate synthase [7], while the enzyme from yeast Saccharomyces cerevisiae is trifunctional with both of the two above mentioned activities [6].