3OG2

Native crystal structure of Trichoderma reesei beta-galactosidase

Summary for 3OG2

• Entry DOI: 10.2210/pdb3og2/pdb
• Related: 3OGR 3OGS 3OGV
• Descriptor: Beta-galactosidase, alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-glucopyranose-(1-3)-alpha-D-glucopyranose-(1-3)-alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: tim barrel domain, glycoside hydrolase, family 35, glycoprotein, hydrolase
• Biological source: Trichoderma reesei (Hypocrea jecorina)
• Total number of polymer chains: 1
• Total formula weight: 113727.65

Authors

Maksimainen, M.,Rouvinen, J. (deposition date: 2010-08-16, release date: 2011-03-16, Last modification date: 2024-10-30)

Primary citation

Maksimainen, M.,Hakulinen, N.,Kallio, J.M.,Timoharju, T.,Turunen, O.,Rouvinen, J.
Crystal structures of Trichoderma reesei beta-galactosidase reveal conformational changes in the active site
J.Struct.Biol., 174:156-163, 2011

PubMed Abstract: We have determined the crystal structure of Trichoderma reesei (Hypocrea jecorina) β-galactosidase (Tr-β-gal) at a 1.2Å resolution and its complex structures with galactose, IPTG and PETG at 1.5, 1.75 and 1.4Å resolutions, respectively. Tr-β-gal is a potential enzyme for lactose hydrolysis in the dairy industry and belongs to family 35 of the glycoside hydrolases (GH-35). The high resolution crystal structures of this six-domain enzyme revealed interesting features about the structure of Tr-β-gal. We discovered conformational changes in the two loop regions in the active site, implicating a conformational selection-mechanism for the enzyme. In addition, the Glu200, an acid/base catalyst showed two different conformations which undoubtedly affect the pK(a) value of this residue and the catalytic mechanism. The electron density showed extensive glycosylation, suggesting a structure stabilizing role for glycans. The longest glycan showed an electron density that extends to the eighth monosaccharide unit in the extended chain. The Tr-β-gal structure also showed a well-ordered structure for a unique octaserine motif on the surface loop of the fifth domain.

PubMed: 21130883
DOI: 10.1016/j.jsb.2010.11.024

Experimental method

X-RAY DIFFRACTION (1.2 Å)