1Y9G

Crystal structure of exo-inulinase from Aspergillus awamori complexed with fructose

Summary for 1Y9G

• Entry DOI: 10.2210/pdb1y9g/pdb
• Related: 1Y4W
• Descriptor: exo-inulinase, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (5 entities in total)
• Functional Keywords: exo-inulinase, aspergillus awamori, glycoside hydrolase family 32, crystallographic structure, complex with fructose, hydrolase
• Biological source: Aspergillus awamori
• Total number of polymer chains: 1
• Total formula weight: 58456.81

Authors

Nagem, R.A.P.,Rojas, A.L.,Golubev, A.M.,Korneeva, O.S.,Eneyskaya, E.V.,Kulminskaya, A.A.,Neustroev, K.N.,Polikarpov, I. (deposition date: 2004-12-15, release date: 2004-12-21, Last modification date: 2024-11-13)

Primary citation

Nagem, R.A.P.,Rojas, A.L.,Golubev, A.M.,Korneeva, O.S.,Eneyskaya, E.V.,Kulminskaya, A.A.,Neustroev, K.N.,Polikarpov, I.
Crystal structure of exo-inulinase from Aspergillus awamori: the enzyme fold and structural determinants of substrate recognition
J.Mol.Biol., 344:471-480, 2004

PubMed Abstract: Exo-inulinases hydrolyze terminal, non-reducing 2,1-linked and 2,6-linked beta-d-fructofuranose residues in inulin, levan and sucrose releasing beta-d-fructose. We present the X-ray structure at 1.55A resolution of exo-inulinase from Aspergillus awamori, a member of glycoside hydrolase family 32, solved by single isomorphous replacement with the anomalous scattering method using the heavy-atom sites derived from a quick cryo-soaking technique. The tertiary structure of this enzyme folds into two domains: the N-terminal catalytic domain of an unusual five-bladed beta-propeller fold and the C-terminal domain folded into a beta-sandwich-like structure. Its structural architecture is very similar to that of another member of glycoside hydrolase family 32, invertase (beta-fructosidase) from Thermotoga maritima, determined recently by X-ray crystallography The exo-inulinase is a glycoprotein containing five N-linked oligosaccharides. Two crystal forms obtained under similar crystallization conditions differ by the degree of protein glycosylation. The X-ray structure of the enzyme:fructose complex, at a resolution of 1.87A, reveals two catalytically important residues: Asp41 and Glu241, a nucleophile and a catalytic acid/base, respectively. The distance between the side-chains of these residues is consistent with a double displacement mechanism of reaction. Asp189, which is part of the Arg-Asp-Pro motif, provides hydrogen bonds important for substrate recognition.

PubMed: 15522299
DOI: 10.1016/j.jmb.2004.09.024

Experimental method

X-RAY DIFFRACTION (1.87 Å)