β-N-acetylhexosaminidase from the fungus Aspergillus oryzae is a secreted extracellular enzyme that cleaves chitobiose into constituent monosaccharides. It belongs to the GH 20 glycoside hydrolase family and consists of two N-glycosylated catalytic cores noncovalently associated with two 10-kDa O-glycosylated propeptides. We used X-ray diffraction and mass spectrometry to determine the structure of A. oryzae β-N-acetylhexosaminidase isolated from its natural source. The three-dimensional structure determined and refined to a resolution of 2.3 Å revealed that this enzyme is active as a uniquely tight dimeric assembly further stabilized by N- and O-glycosylation. The propeptide from one subunit forms extensive noncovalent interactions with the catalytic core of the second subunit in the dimer, and this chain swap suggests the distinctive structural mechanism of the enzyme's activation. Unique structural features of β-N-acetylhexosaminidase from A. oryzae define a very stable and robust framework suitable for biotechnological applications. The crystal structure reported here provides structural insights into the enzyme architecture as well as the detailed configuration of the active site. These insights can be applied to rational enzyme engineering. DATABASE: Structural data are available in the PDB database under the accession number 5OAR. ENZYME: β-N-acetylhexosaminidase (EC 3.2.1.52).

• MeSH
• Aspergillus oryzae enzymologie   MeSH
• beta-N-acetylhexosaminidasy chemie   metabolismus   MeSH
• dimerizace MeSH
• fungální proteiny chemie   metabolismus   MeSH
• G(M2) aktivátorový protein chemie   metabolismus   MeSH
• G(M2) gangliosid chemie   metabolismus   MeSH
• glykosylace MeSH
• interakční proteinové domény a motivy MeSH
• katalytická doména MeSH
• konzervovaná sekvence MeSH
• krystalografie rentgenová MeSH
• ligandy MeSH
• molekulární modely * MeSH
• posttranslační úpravy proteinů MeSH
• prekurzory enzymů chemie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• stabilita proteinů MeSH
• strukturní homologie proteinů MeSH
• substrátová specifita MeSH
• vazebná místa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH