This enzyme, along with EC?4.1.2.43, 3-hexulose-6-phosphate synthase, plays a key role in the ribulose-monophosphate cycle of formaldehyde fixation, which is present in many microorganisms that are capable of utilizing C1-compounds [1]. The hyperthermophilic and anaerobic archaeon?Pyrococcus horikoshii?OT3 constitutively produces a bifunctional enzyme that sequentially catalyses the reactions of EC?4.1.2.43?(3-hexulose-6-phosphate synthase) and this enzyme [4].
