Exploitation of a cellulose-binding domain from Neurospora crassa

After eight decades as a purely research organism, Neurospora crassa is becoming a production system for heterologous peptides. The present work exploits the cbh-1 gene, which encodes a class C cellobiohydrolase (EC 3.2.1.91) and has, at its carboxy-terminus, a domain with homology to other fungal cellulose-binding domains. We describe the construction of two translational fusions of the putative cellulose-binding domain with a reporter gene, which is the catalytic domain of the gla-1 glucoamylase gene of the same species, their transformation back into the organism, and expression of the constructs as cellulose-binding glucoamylase activity. This adds to the developing biotechnology of the organism the potential for enzyme/protein immobilisation.