<p>This entry represents a single-molecule form of phosphoribosylformylglycinamidine synthase, also called FGAM synthase, an enzyme of purine de novo biosynthesis. This form is found mostly in eukaryotes and proteobacteria. In <taxon tax_id="1423">Bacillus subtilis</taxon> PurL (FGAM synthase II) and PurQ (FGAM synthase I) perform the equivalent function; the unrelated small protein PurS is also required and may be a third subunit [<cite idref="PUB00014926"/>].</p> Phosphoribosylformylglycinamidine synthase