Abstract
Reading-frame corrective shifts in the nucleotide sequence upstream, within, or downstream from the putative coding region of several β-glycanase-encoding genes reported in the literature reveal hidden active-site residues or even additional domains, including a cellulose-binding domain on a β-mannanase-encoding gene. These findings also help in assigning, to cellulase family A, two enzymes previously found to lack sequence similarity with known cellulase families.