title: Identification of a gene coding for a deglycosylating enzyme in Hypocrea jecorina.
abstract: An enzyme with mannosyl glycoprotein endo-N-acetyl-beta-D-glucosaminidase (ENGase)-type activity was partially purified from the extracellular medium of the mould Hypocrea jecorina (Trichoderma reesei). Internal peptides were generated and used to identify the gene in the T. reesei genome. The active enzyme is processed both at the N- and at the C-terminus. High-mannose-type glycoproteins are good substrates, whereas complex-type glycans are not hydrolysed. The enzyme represents the first fungal member of glycoside hydrolase family 18 with ENGase-type activity. Bacterial ENGases and the fungal chitinases belonging to the same family show very low homology with Endo T. Database searches identify several highly homologous genes in fungi and the activity is also found within other Trichoderma species. This ENGase activity, not coregulated with cellulase production, could be responsible for the extensive N-deglycosylation observed for several T. reesei cellulases.
authors.affiliation: Department of Biochemistry and Microbiology, Faculty of Applied Engineering Sciences, Ghent University, Ghent, Belgium. ingeborg.stals@ugent.be
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Stals
authors.forename: Bart
authors.initials: B
authors.lastname: Samyn
authors.forename: Kjell
authors.initials: K
authors.lastname: Sergeant
authors.forename: Theresa
authors.initials: T
authors.lastname: White
authors.forename: Katleen
authors.initials: K
authors.lastname: Hoorelbeke
authors.forename: An
authors.initials: A
authors.lastname: Coorevits
authors.forename: Bart
authors.initials: B
authors.lastname: Devreese
authors.forename: Marc
authors.initials: M
authors.lastname: Claeyssens
authors.forename: Kathleen
authors.initials: K
authors.lastname: Piens
mesh_terms: D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D016000:Cluster Analysis; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D035901:Hypocrea / Q000201:enzymology* / Q000235:genetics*; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D005656:Fungal Proteins; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase