Two glucuronoyl esterases of Phanerochaete chrysosporium
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The white-rot fungus Phanerochaete chrysosporium produces glucuronoyl esterase, a recently discovered carbohydrate esterase, during growth on sugar beet pulp. Two putative genes encoding this enzyme, ge1 and ge2, were isolated and cloned. Heterologous expression in Aspergillus vadensis, Pycnoporus cinnabarinus and Schizophyllum commune resulted in extracellular glucuronoyl esterase activity, demonstrating that these genes encode this enzymatic function. The amino acid sequence of GE1 was used to identify homologous genes in the genomes of twenty-four fungi. Approximately half of the genomes, both from ascomycetes and basidiomycetes, contained putative orthologues, but their presence could not be assigned to any of fungal class or subclass. Comparison of the amino acid sequences of identified and putative glucuronoyl esterases to other types of carbohydrate esterases (CE) confirmed that they form a separate family of CEs. These enzymes are interesting candidates for biotechnological applications such as the separation of lignin and hemicellulose.
KeywordsGlucuronoyl esterase Phanerochaete chrysosporium Lignin-carbohydrate complex
The authors thank Dr. J. Hirsch (the Institute of Chemistry, Slovak Academy of Sciences, Slovakia) for the glucuronoyl esterase substrates, Dr. A. Alves (Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands) for help with the P. cinnabarinus transformation and Dr. L. G. Lugones (Microbiology, Utrecht University, The Netherlands) for help with the S. commune transformation. This work was supported by a grant from the Slovak Research and Development Agency under the Contract No. APVV-51-003805.
- Obst JR (1982) Frequency and alkali resistance of lignin-carbohydrate bonds in wood. Tappi 65:109–112Google Scholar
- Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual, 2nd edn. Cold Spring Harbor Laboratory Press, Cold Spring HarborGoogle Scholar
- Watanabe T, Koshijima T (1988) Evidence for an ester linkage between lignin and glucuronic acid in lignin-carbohydrate complexes by DDQ-oxidation. Agric Biol Chem 52:2953–2955Google Scholar