Discovery of processive catalysis by an exo-hydrolase with a pocket-shaped active site
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Fecha
2019-12
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Nature Publishing Group
Nombre de Curso
Licencia CC
Atribución 4.0 Internacional (CC BY 4.0)
Licencia CC
https://creativecommons.org/licenses/by/4.0/deed.es
Resumen
Substrates associate and products dissociate from enzyme catalytic sites rapidly, which hampers investigations of their trajectories. The high-resolution structure of the native Hordeum exo-hydrolase HvExoI isolated from seedlings reveals that non-covalently trapped glucose forms a stable enzyme-product complex. Here, we report that the alkyl β-d-glucoside and methyl 6-thio-β-gentiobioside substrate analogues perfused in crystalline HvExoI bind across the catalytic site after they displace glucose, while methyl 2-thio-β-sophoroside attaches nearby. Structural analyses and multi-scale molecular modelling of nanoscale reactant movements in HvExoI reveal that upon productive binding of incoming substrates, the glucose product modifies its binding patterns and evokes the formation of a transient lateral cavity, which serves as a conduit for glucose departure to allow for the next catalytic round. This path enables substrate-product assisted processive catalysis through multiple hydrolytic events without HvExoI losing contact with oligo- or polymeric substrates. We anticipate that such enzyme plasticity could be prevalent among exo-hydrolases. © 2019, Crown.
Notas
Indexación: Scopu
Palabras clave
Biocatalysis, Catalytic Domain, Crystallography, X-Ray, Enzyme Assays, Glucosidases, Glycosides, Hordeum, Models, Molecular, Molecular Dynamics Simulation, Nuclear Magnetic Resonance, Biomolecular, Plant Proteins, Recombinant Proteins, Seedlings, Substrate Specificity
Citación
Nature Communications Volume 10, Issue 11 December 2019 Article number 2222
DOI
10.1038/s41467-019-09691-z