The oxidative pentose phosphate pathway in the haloarchaeon Haloferax volcanii involves a novel type of glucose-6-phosphate dehydrogenase--The archaeal Zwischenferment

FEBS Lett. 2015 Apr 28;589(10):1105-11. doi: 10.1016/j.febslet.2015.03.026. Epub 2015 Mar 31.


The oxidative pentose phosphate pathway (OPPP), catalyzing the oxidation of glucose-6-phosphate to ribulose-5-phosphate is ubiquitous in eukarya and bacteria but has not yet been reported in archaea. In haloarchaea a putative 6-phosphogluconate dehydrogenase (6PGDH) is annotated, whereas a gene coding for glucose-6-phosphate dehydrogenase (Glc6PDH) could not be identified. Here we report the purification and characterization of a novel type of Glc6PDH in Haloferax volcanii that is not related to bacterial and eukaryal Glc6PDHs and the encoding gene is designated as azf (archaeal zwischenferment). Further, recombinant H. volcanii 6PGDH was characterized. Deletion mutant analyses indicate that both, Glc6PDH and 6PGDH, are functionally involved in pentose phosphate formation in vivo. This is the first report on the operation of the OPPP in the domain of archaea.

Keywords: 6-Phosphogluconate dehydrogenase; Archaea; Glucose-6-phosphate dehydrogenase; Haloferax volcanii; Oxidative pentose phosphate pathway; Zwischenferment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaeal Proteins* / chemistry
  • Archaeal Proteins* / genetics
  • Archaeal Proteins* / isolation & purification
  • Archaeal Proteins* / metabolism
  • Glucosephosphate Dehydrogenase* / chemistry
  • Glucosephosphate Dehydrogenase* / genetics
  • Glucosephosphate Dehydrogenase* / isolation & purification
  • Glucosephosphate Dehydrogenase* / metabolism
  • Haloferax volcanii / enzymology*
  • Haloferax volcanii / genetics*
  • Pentose Phosphate Pathway / physiology*


  • Archaeal Proteins
  • Glucosephosphate Dehydrogenase