The ferredoxin-dependent conversion of glyceraldehyde-3-phosphate in the hyperthermophilic archaeon Pyrococcus furiosus represents a novel site of glycolytic regulation.
The fermentative conversion of glucose in anaerobic hyperthermophilic Archaea is a variant of the classical Embden-Meyerhof pathway found in Bacteria and Eukarya. A major difference of the archaeal glycolytic pathway concerns the conversion of glyceraldehyde-3-phosphate. In the hyperthermophilic archaeon Pyrococcus furiosus, this reaction is catalyzed by an unique enzyme, glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR). Here, we report the isolation, characterization, and transcriptional analysis of the GAPOR-encoding gene. GAPOR is related to a family of ferredoxin-dependent tungsten enzymes in (hyper)thermophilic Archaea and, in addition, to a hypothetical protein in Escherichia coli. Electron paramagnetic resonance analysis of the purified P. furiosus GAPOR protein confirms the anticipated involvement of tungsten in catalysis. During glycolysis in P. furiosus, GAPOR gene expression is induced, whereas the activity of glyceraldehyde-3-phosphate dehydrogenase is repressed. It is discussed that this unprecedented unidirectional reaction couple in the pyrococcal glycolysis and gluconeogenesis gives rise to a novel site of glycolytic regulation that might be widespread among Archaea.
Laboratory of Microbiology, Wageningen Agricultural University, Hesselink van Suchtelenweg 4, NL-6307 CT Wageningen, The Netherlands. john.vanderoost@algemeen.micr.wau.nl
J
J
van der Oost
G
G
Schut
S W
SW
Kengen
W R
WR
Hagen
M
M
Thomm
W M
WM
de Vos
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D005288:Ferredoxins / Q000378:metabolism*; D019766:Genes, Archaeal; D005943:Gluconeogenesis / Q000502:physiology; D005986:Glyceraldehyde 3-Phosphate / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics* / Q000378:metabolism; D006019:Glycolysis / Q000502:physiology; D008969:Molecular Sequence Data; D020027:Pyrococcus furiosus / Q000201:enzymology / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D005288:Ferredoxins; D005986:Glyceraldehyde 3-Phosphate; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; C093132:glyceraldehyde-3-phosphate ferredoxin oxidoreductase