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.