2WNE

Mutant Laminarinase 16A cyclizes laminariheptaose

Summary for 2WNE

• Entry DOI: 10.2210/pdb2wne/pdb
• Related: 2CL2 2W39 2W52 2WLQ
• Descriptor: PUTATIVE LAMINARINASE, beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-beta-D-glucopyranose-(1-3)-alpha-D-glucopyranose, 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, ... (4 entities in total)
• Functional Keywords: laminarin, family 16, cyclical poysaccharides, glycosyl hydrolase, beta sandwich, basidiomycete, beta-glucanase, gh7, gh16, lam16a, beta-1\, 6-glucan, hydrolase
• Biological source: PHANEROCHAETE CHRYSOSPORIUM (WHITE-ROT FUNGUS)
• Total number of polymer chains: 1
• Total formula weight: 34268.79

Authors

Vasur, J.,Kawai, R.,Andersson, E.,Widmalm, G.,Jonsson, K.H.M.,Hansson, H.,Engstrom, A.,Einarsson, E.,Forsberg, Z.,Igarashi, K.,Sandgren, M.,Samejima, M.,Stahlberg, J. (deposition date: 2009-07-09, release date: 2010-01-26, Last modification date: 2024-10-23)

Primary citation

Vasur, J.,Kawai, R.,Jonsson, K.H.M.,Widmalm, G.,Engstrom, A.,Frank, M.,Andersson, E.,Hansson, H.,Forsberg, Z.,Igarashi, K.,Samejima, M.,Sandgren, M.,Stahlberg, J.
Synthesis of Cyclic Beta-Glucan Using Laminarinase 16A Glycosynthase Mutant from the Basidiomycete Phanerochaete Chrysosporium.
J.Am.Chem.Soc., 132:1724-, 2010

PubMed Abstract: Glycosynthases are precise molecular instruments for making specifically linked oligosaccharides. X-ray crystallography screening of ligands bound to the 1,3(4)-beta-D-glucanase nucleophile mutant E115S of Phanerochaete chrysosporium Laminarinase 16A (Lam16A) showed that laminariheptaose (L7) bound in an arch with the reducing and nonreducing ends occupying either side of the catalytic cleft of the enzyme. The X-ray structure of Lam16A E115S in complex with alpha-laminariheptaosyl fluoride (alphaL7F) revealed how alphaL7F could make a nucleophilic attack upon itself. Indeed, when Lam16A E115S was allowed to react with alphaL7F the major product was a cyclic beta-1,3-heptaglucan, as shown by mass spectrometry. NMR confirmed uniquely beta-1,3-linkages and no reducing end. Molecular dynamics simulations indicate that the cyclic laminariheptaose molecule is not completely planar and that torsion angles at the glycosidic linkages fluctuate between two energy minima. This is the first report of a glycosynthase that joins the reducing and nonreducing ends of a single oligosaccharide and the first reported synthesis of cyclic beta-glucan.

PubMed: 20078120
DOI: 10.1021/JA909129B

Experimental method

X-RAY DIFFRACTION (2.124 Å)