1 Molecular Microbiology and Biotechnology, Institute of Biology Leiden, Leiden University, The Netherlands.
2 Fungal Physiology, Westerdijk Fungal Biodiversity Institute, Utrecht University, The Netherlands.
3 Centre for Structural and Functional Genomics, Concordia University, Montreal, Canada.

The pathway intermediate 2-keto-3-deoxy-L-galactonate mediates the induction of genes involved in D-galacturonic acid utilization in Aspergillus niger.

FEBS Lett. 2017 05;591(10):1408-1418

Authors: Alazi E, Khosravi C, Homan TG, du Pré S, Arentshorst M, Di Falco M, Pham TTM, Peng M, Aguilar-Pontes MV, Visser J, Tsang A, de Vries RP, Ram AFJ

Abstract

In Aspergillus niger, the enzymes encoded by gaaA, gaaB, and gaaC catabolize d-galacturonic acid (GA) consecutively into l-galactonate, 2-keto-3-deoxy-l-galactonate, pyruvate, and l-glyceraldehyde, while GaaD converts l-glyceraldehyde to glycerol. Deletion of gaaB or gaaC results in severely impaired growth on GA and accumulation of l-galactonate and 2-keto-3-deoxy-l-galactonate, respectively. Expression levels of GA-responsive genes are specifically elevated in the ?gaaC mutant on GA as compared to the reference strain and other GA catabolic pathway deletion mutants. This indicates that 2-keto-3-deoxy-l-galactonate is the inducer of genes required for GA utilization.

PMID: 28417461 [PubMed - indexed for MEDLINE]