The crystal structure of acidic β-galactosidase from Aspergillus oryzae

• Published in: International journal of biological macromolecules Vol. 60; pp. 109 - 115
• Main Authors: Maksimainen, Mirko M., Lampio, Anja, Mertanen, Mirka, Turunen, Ossi, Rouvinen, Juha
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-09-2013
• Subjects: Amino Acid Sequence; Aspergillus oryzae; Aspergillus oryzae - enzymology; beta-galactosidase; beta-Galactosidase - chemistry; beta-Galactosidase - metabolism; Catalytic Domain; crystal structure; Crystallography, X-Ray; Fungal Proteins - chemistry; Fungal Proteins - metabolism; Glycoside hydrolase; glycosides; Glycosylation; hydrophobicity; Models, Molecular; Molecular Sequence Data; N-glycosylation; Protein Conformation; Sequence Alignment; β-galactosidase; MPD; Psp-β-gal; β-galactosidase; Tr-β-gal; Aspergillus oryzae; crystal structure; Ao-β-gal; N-glycosylation; Glycoside hydrolase; PDB; β-galactosidase from Trichoderma reesei; 2-methyl-2,4-pentanediol; β-galactosidase from Penicllium sp; β-galactosidase from Aspergillus oryzae; Protein Data Bank
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2013.05.003

The crystal structure of the industrially important Aspergillus oryzae β-galactosidase has been determined at 2.60Å resolution. The Ao-β-gal is a large (985 residues) monomeric multi-domain enzyme that has a catalytic (α/β)8-barrel domain. An electron density map revealed extensive N-glycosylation between the domain interfaces suggesting that the oligosaccharide-chains would have a stabilizing role for the structure of Ao-β-gal. Comparison of structure with other β-galactosidase structures of glycoside hydrolase family 35 revealed a number of hydrophobic residues, which may contribute favorably to the stabilization of the structure. The role of a high number of acidic residues in Ao-β-gal is also discussed.