Identification in the mold Hypocrea jecorina of the first fungal D-galacturonic acid reductase

S Kuorelahti, Nisse Kalkkinen, M Penttila, J Londesborough, P Richard*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

A D-galacturonic acid reductase and the corresponding gene were identified from the mold Hypocrea jecorina (Trichoderma reesei). We hypothesize that the enzyme is part of a fungal D-galacturonic acid catabolic pathway which has not been described previously and which is distinctly different from the bacterial pathway. H. jecorina grown on D-galacturonic acid exhibits an NADPH-dependent D-galacturonic acid reductase activity. This activity is absent when the mold is grown on other carbon sources. The D-galacturonic acid reductase was purified, and tryptic digests of the purified protein were sequenced. The open reading frame of the corresponding gene was then cloned from a cDNA library. The open reading frame was functionally expressed in the yeast Saccharomyces cerevisiae. A histidine-tagged protein was purified, and the enzyme kinetics were characterized. The enzyme converts in a reversible reaction from D-galacturonic acid and NADPH to L-galactonic acid and NADP. The enzyme also exhibits activity with D-glucuronic acid and DL-glyceraldehyde.

Original languageEnglish
Pages (from-to)11234-11240
Number of pages7
JournalBiochemistry
Volume44
Issue number33
DOIs
Publication statusPublished - 23 Aug 2005
MoE publication typeA1 Journal article-refereed

Keywords

  • ARABINOSE CATABOLIC PATHWAY
  • L-GULONOLACTONE OXIDASE
  • L-XYLULOSE REDUCTASE
  • D-ALTRONIC ACID
  • ESCHERICHIA-COLI
  • ASPERGILLUS-NIDULANS
  • PURIFICATION
  • METABOLISM
  • YEAST
  • BACTERIA

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