Characterization of a GH12 family glycosyl hydrolase from Neurospora crassa

The Neurospora crassa genome encodes a single glycosyl hydrolase family 12 enzyme GH12–1. To characterize the enzyme, the gh12–1 gene was cloned and tagged with a HIS6 tag. Characterization of the purified GH12–1 enzyme showed that it cleaves carboxymethylcellulose, laminarin (β-1,3-glucan) and lichenin (a mixed β-1,3−/β-1,4-glucan) to release trisaccharides from an end of the polysaccharide substrate. Laminarin and lichenin are the major polysaccharides found in the N. crassa cell wall. We conclude that GH12–1 could function to degrade cellulose and/or to digest laminarin and lichenin polysaccharides released from the cell wall during cell wall remodeling.