ID 5.3.1.27 DE 6-phospho-3-hexuloisomerase. AN 3-hexulose-6-phosphate isomerase. AN 6-phospho-3-hexulose isomerase. AN PHI. AN phospho-3-hexuloisomerase. CA D-arabino-hex-3-ulose 6-phosphate = beta-D-fructose 6-phosphate. CC -!- This enzyme, along with EC 4.1.2.43, plays a key role in the CC ribulose-monophosphate cycle of formaldehyde fixation, which is CC present in many microorganisms that are capable of utilizing CC C1-compounds. CC -!- The hyperthermophilic and anaerobic archaeon Pyrococcus horikoshii CC OT3 constitutively produces a bifunctional enzyme that sequentially CC catalyzes the reactions of EC 4.1.2.43 and this enzyme. DR P42404, PHI_BACSU ; Q9S0X3, PHI_METAM ; Q58644, PHI_METJA ; DR Q9LBW5, PHI_MYCGS ; //