4N2R

Crystal Structure of the alpha-L-arabinofuranosidase UmAbf62A from Ustilago maydis in complex with L-arabinofuranose

Summary for 4N2R

• Entry DOI: 10.2210/pdb4n2r/pdb
• Related: 4N1I 4N2Z 4N4B
• Descriptor: alpha-L-arabinofuranosidase UmAbf62A, CALCIUM ION, beta-L-arabinofuranose, ... (6 entities in total)
• Functional Keywords: beta-propeller, hydrolase, hemicellulose binding
• Biological source: Ustilago maydis (Corn smut fungus)
• Total number of polymer chains: 1
• Total formula weight: 37516.64

Authors

Siguier, B.,Dumon, C.,Mourey, L.,Tranier, S. (deposition date: 2013-10-06, release date: 2014-01-15, Last modification date: 2024-10-30)

Primary citation

Siguier, B.,Haon, M.,Nahoum, V.,Marcellin, M.,Burlet-Schiltz, O.,Coutinho, P.M.,Henrissat, B.,Mourey, L.,O'Donohue, M.J.,Berrin, J.G.,Tranier, S.,Dumon, C.
First Structural Insights into alpha-L-Arabinofuranosidases from the Two GH62 Glycoside Hydrolase Subfamilies.
J.Biol.Chem., 289:5261-5273, 2014

PubMed Abstract: α-L-arabinofuranosidases are glycoside hydrolases that specifically hydrolyze non-reducing residues from arabinose-containing polysaccharides. In the case of arabinoxylans, which are the main components of hemicellulose, they are part of microbial xylanolytic systems and are necessary for complete breakdown of arabinoxylans. Glycoside hydrolase family 62 (GH62) is currently a small family of α-L-arabinofuranosidases that contains only bacterial and fungal members. Little is known about the GH62 mechanism of action, because only a few members have been biochemically characterized and no three-dimensional structure is available. Here, we present the first crystal structures of two fungal GH62 α-L-arabinofuranosidases from the basidiomycete Ustilago maydis (UmAbf62A) and ascomycete Podospora anserina (PaAbf62A). Both enzymes are able to efficiently remove the α-L-arabinosyl substituents from arabinoxylan. The overall three-dimensional structure of UmAbf62A and PaAbf62A reveals a five-bladed β-propeller fold that confirms their predicted classification into clan GH-F together with GH43 α-L-arabinofuranosidases. Crystallographic structures of the complexes with arabinose and cellotriose reveal the important role of subsites +1 and +2 for sugar binding. Intriguingly, we observed that PaAbf62A was inhibited by cello-oligosaccharides and displayed binding affinity to cellulose although no activity was observed on a range of cellulosic substrates. Bioinformatic analyses showed that UmAbf62A and PaAbf62A belong to two distinct subfamilies within the GH62 family. The results presented here provide a framework to better investigate the structure-function relationships within the GH62 family.

PubMed: 24394409
DOI: 10.1074/jbc.M113.528133

Experimental method

X-RAY DIFFRACTION (1.2 Å)