Novel non-phosphorylative pathway of pentose metabolism from bacteria

Sci Rep. 2019 Jan 17;9(1):155. doi: 10.1038/s41598-018-36774-6.

Abstract

Pentoses, including D-xylose, L-arabinose, and D-arabinose, are generally phosphorylated to D-xylulose 5-phosphate in bacteria and fungi. However, in non-phosphorylative pathways analogous to the Entner-Dodoroff pathway in bacteria and archaea, such pentoses can be converted to pyruvate and glycolaldehyde (Route I) or α-ketoglutarate (Route II) via a 2-keto-3-deoxypentonate (KDP) intermediate. Putative gene clusters related to these metabolic pathways were identified on the genome of Herbaspirillum huttiense IAM 15032 using a bioinformatic analysis. The biochemical characterization of C785_RS13685, one of the components encoded to D-arabinonate dehydratase, differed from the known acid-sugar dehydratases. The biochemical characterization of the remaining components and a genetic expression analysis revealed that D- and L-KDP were converted not only to α-ketoglutarate, but also pyruvate and glycolate through the participation of dehydrogenase and hydrolase (Route III). Further analyses revealed that the Route II pathway of D-arabinose metabolism was not evolutionally related to the analogous pathway from archaea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism*
  • Computational Biology / methods
  • Herbaspirillum / genetics*
  • Herbaspirillum / metabolism*
  • Metabolic Networks and Pathways
  • Multigene Family
  • Pentoses / metabolism*
  • Phosphorylation

Substances

  • Bacterial Proteins
  • Pentoses

Supplementary concepts

  • Herbaspirillum huttiense