The Hypocrea jecorina (syn. Trichoderma reesei) lxr1 gene encodes a d-mannitol dehydrogenase and is not involved in l-arabinose catabolism

Metz, Benjamin; de Vries, Ronald P.; Polak, Stefan; Seidl, Verena; Seiboth, Bernhard

doi:10.1016/j.febslet.2009.03.027

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Volume 583, Issue 8 , Pages 1309-1313, 17 April 2009

The Hypocrea jecorina (syn. Trichoderma reesei) lxr1 gene encodes a d-mannitol dehydrogenase and is not involved in l-arabinose catabolism

Edited by Judit Ovádi

Benjamin Metz
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt 9, A-1060 Wien, Austria
- B.M. and R.V. contributed equally to this article.
Ronald P. de Vries
- Microbiology, Utrecht University, Utrecht, The Netherlands
- B.M. and R.V. contributed equally to this article.
Stefan Polak
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt 9, A-1060 Wien, Austria
Verena Seidl
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt 9, A-1060 Wien, Austria
Bernhard Seiboth
- Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, TU Vienna, Getreidemarkt 9, A-1060 Wien, Austria
- Corresponding author. Fax: +43 1 58801 17299.

Received 27 January 2009; received in revised form 5 March 2009; accepted 13 March 2009. published online 20 March 2009.

Abstract

The Hypocrea jecorina LXR1 was described as the first fungal l-xylulose reductase responsible for NADPH dependent reduction of l-xylulose to xylitol in l-arabinose catabolism. Phylogenetic analysis now reveals that LXR1 forms a clade with fungal d-mannitol 2-dehydrogenases. Lxr1 and the orthologous Aspergillus niger mtdA are not induced by l-arabinose but expressed at low levels during growth on different carbon sources. Deletion of lxr1 does not affect growth on l-arabinose and l-xylulose reductase activity remains unaltered whereas d-mannitol 2-dehydrogenase activities are reduced. We conclude that LXR1 is a d-mannitol 2-dehydrogenase and that a true LXR1 is still awaiting discovery.