Molecular cloning, characterisation and expression of a gene encoding cellobiose dehydrogenase from Termitomyces clypeatus

Abstract

Cellobiose dehydrogenase (CDH) (E.C. 1.1.99.18) is a biomass degrading enzyme secreted by various cellulolytic fungi. It has applications in renewable biofuel production, biosensor, bioremediation, lactose determination in food, bleaching of pulp, biomedical applications etc. This paper describes cloning of a previously characterised gene from the published transcriptome data of a fungus Termitomyces clypeatus, its expression in Saccharomyces cerevisiae and its molecular and biochemical characterisation etc. which ultimately led us to conclude that the gene in fact codes for a CDH at biochemical level. The full length cDNA exhibited 2523 nucleotides and the deduced protein sequence consists of 840 amino acids. Genomic DNA analysis has revealed presence of four introns within this gene. The protein contains 4 putative N-glycosylation and 14 putative O-glycosylation sites. Cloning and molecular characterisation of this gene opens yet another new source of CDH enzyme for commercial exploitation by industry in future.