TheX-raystructureofnativecellobiohydrolase IB(CBHIB) from the filamentous fungus Talaromyces emersonii,PDB 1Q9H,was solved A ˚ bymolecular replacement. 1Q9H is a glycoprotein that consists of a large, single domain with dimensions of 60 A ˚ ·40 A ˚ ·50 A ˚ andanoverall b-sandwich structure, the characteristic fold of Family 7 glycosyl hydrolases (GH7). It is the first structure of a native glycoprotein and cellulase fromthis thermophilic eukaryote.