The archaeon Pyrococcus horikoshii possesses a bifunctional enzyme for formaldehyde fixation via the ribulose monophosphate pathway.

ABSTRACT: Pyrococcus horikoshii OT3, a hyperthermophilic and anaerobic archaeon, was found to have an open reading frame (PH1938) whose deduced amino acid sequence of the N-terminal and C-terminal halves showed significant similarity to two key enzymes of the ribulose monophosphate pathway for formaldehyde fixation in methylotrophic bacteria, 3-hexulose-6-phosphate synthase (HPS) and 6-phospho-3-hexuloisomerase (PHI), respectively. The organism constitutively produced the encoded protein and exhibited activity of the sequential HPS- and PHI-mediated reactions in a particulate fraction. The full-length gene encoding the hybrid enzyme, the sequence corresponding to the HPS region, and the sequence corresponding to the PHI region were expressed in Escherichia coli and were found to produce active enzym

SUBMITTER: Orita I 

PROVIDER: S-EPMC1112069 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature