4NI3

Crystal Structure of GH29 family alpha-L-fucosidase from Fusarium graminearum in the closed form

Summary for 4NI3

• Entry DOI: 10.2210/pdb4ni3/pdb
• Descriptor: Alpha-fucosidase GH29, alpha-D-mannopyranose-(1-2)-alpha-D-mannopyranose-(1-2)-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, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: fucosidase, gh29, glycoside hydrolase, tim barrel, crystallin, hydrolase
• Biological source: Fusarium graminearum (Wheat head blight fungus)
• Total number of polymer chains: 2
• Total formula weight: 135645.55

Authors

Cao, H.,Walton, J.D.,Brumm, P.,Phillips Jr., G.N. (deposition date: 2013-11-05, release date: 2013-12-25, Last modification date: 2024-11-20)

Primary citation

Cao, H.,Walton, J.D.,Brumm, P.,Phillips, G.N.
Structure and Substrate Specificity of a Eukaryotic Fucosidase from Fusarium graminearum.
J.Biol.Chem., 289:25624-25638, 2014

PubMed Abstract: The secreted glycoside hydrolase family 29 (GH29) α-L-fucosidase from plant pathogenic fungus Fusarium graminearum (FgFCO1) actively releases fucose from the xyloglucan fragment. We solved crystal structures of two active-site conformations, i.e. open and closed, of apoFgFCO1 and an open complex with product fucose at atomic resolution. The closed conformation supports catalysis by orienting the conserved general acid/base Glu-288 nearest the predicted glycosidic position, whereas the open conformation possibly represents an unreactive state with Glu-288 positioned away from the catalytic center. A flexible loop near the substrate binding site containing a non-conserved GGSFT sequence is ordered in the closed but not the open form. We also identified a novel C-terminal βγ-crystallin domain in FgFCO1 devoid of calcium binding motif whose homologous sequences are present in various glycoside hydrolase families. N-Glycosylated FgFCO1 adopts a monomeric state as verified by solution small angle x-ray scattering in contrast to reported multimeric fucosidases. Steady-state kinetics shows that FgFCO1 prefers α1,2 over α1,3/4 linkages and displays minimal activity with p-nitrophenyl fucoside with an acidic pH optimum of 4.6. Despite a retaining GH29 family fold, the overall specificity of FgFCO1 most closely resembles inverting GH95 α-fucosidase, which displays the highest specificity with two natural substrates harboring the Fucα1-2Gal glycosidic linkage, a xyloglucan-derived nonasaccharide, and 2'-fucosyllactose. Furthermore, FgFCO1 hydrolyzes H-disaccharide (lacking a +2 subsite sugar) at a rate 10(3)-fold slower than 2'-fucosyllactose. We demonstrated the structurally dynamic active site of FgFCO1 with flexible general acid/base Glu, a common feature shared by several bacterial GH29 fucosidases to various extents.

PubMed: 25086049
DOI: 10.1074/jbc.M114.583286

Experimental method

X-RAY DIFFRACTION (1.3993 Å)