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http://hdl.handle.net/2445/114446
Title: | A β-mannannase with a lysozyme fold and a novel molecular catalytic mechanism |
Author: | Jin, Yi Petricevic, Marija John, Alan Raich Armendáriz, Lluís Adrià Jenkins, Huw Portela de Souza, Leticia Cuskin, Fiona Gilbert, Harry J. Rovira i Virgili, Carme Goddard-Borger, Ethan D. Williams, Spencer J. Davies, Gideon J. |
Keywords: | Lisozim Enzims Catàlisi Lysozyme Enzymes Catalysis |
Issue Date: | 8-Nov-2016 |
Publisher: | American Chemical Society |
Abstract: | The enzymatic cleavage of β-1,4-mannans is achieved by endo-β-1,4-mannanases, enzymes involved in germination of seeds and microbial hemicellulose degradation, and which have increasing industrial and consumer product applications. β-Mannanases occur in a range of families of the CAZy sequence-based glycoside hydrolase (GH) classification scheme including families 5, 26, and 113. In this work we reveal that β-mannanases of the newly described GH family 134 differ from other mannanase families in both their mechanism and tertiary structure. A representative GH family 134 endo-β-1,4-mannanase from a Streptomyces sp. displays a fold closely related to that of hen egg white lysozyme but acts with inversion of stereochemistry. A Michaelis complex with mannopentaose, and a product complex with mannotriose, reveal ligands with pyranose rings distorted in an unusual inverted chair conformation. Ab initio quantum mechanics/molecular mechanics metadynamics quantified the energetically accessible ring conformations and provided evidence in support of a 1C4 → 3H4 → 3S1 conformational itinerary along the reaction coordinate. This work, in concert with that on GH family 124 cellulases, reveals how the lysozyme fold can be co-opted to catalyze the hydrolysis of different polysaccharides in a mechanistically distinct manner |
Note: | Reproducció del document publicat a: https://doi.org/10.1021/acscentsci.6b00232 |
It is part of: | ACS Central Science, 2016, vol. 2, num. 12, p. 896-903 |
URI: | http://hdl.handle.net/2445/114446 |
Related resource: | https://doi.org/10.1021/acscentsci.6b00232 |
ISSN: | 2374-7951 |
Appears in Collections: | Articles publicats en revistes (Química Inorgànica i Orgànica) |
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