[PMID]: | 29253895 |
[Au] Autor: | Wang X; Zheng F; Wang Y; Tu T; Ma R; Su X; You S; Yao B; Xie X; Luo H |
[Ad] Endereço: | College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, People's Republic of China. |
[Ti] Título: | Improvement of the catalytic efficiency of a hyperthermophilic xylanase from Bispora sp. MEY-1. |
[So] Source: | PLoS One;12(12):e0189806, 2017. |
[Is] ISSN: | 1932-6203 |
[Cp] País de publicação: | United States |
[La] Idioma: | eng |
[Ab] Resumo: | Extremophilic xylanases have attracted great scientific and industrial interest. In this study, a GH10 xylanase-encoding gene, Xyl10E, was cloned from Bispora sp. MEY-1 and expressed in Pichia pastoris GS115. Deduced Xyl10E shares the highest identities of 62% and 57% with characterized family GH10 xylanases from Talaromyces leycettanus and Penicillium canescens (structure 4F8X), respectively. Xyl10E was most active at 93 to 95°C and pH 4.0, retained more than 75% or 48% of the initial activity when heated at 80°C or 90°C for 30 min, respectively, and hardly lost activity at pH 1.0 to 7.0, but was completely inhibited by SDS. Two residues, A160 and A161, located on loop 4, were identified to play roles in catalysis. Mutants A160D/E demonstrated higher affinity to substrate with lower Km values, while mutants A161D/E mainly displayed elevated Vmax values. All of these mutants had significantly improved catalytic efficiency. According to the molecular dynamics simulation, the mutation of A160E was able to affect the important substrate binding site Y204 and then improve the substrate affinity, and the mutation of A161D was capable of forming a hydrogen bond with the substrate to promote the substrate binding or accelerate the product release. This study introduces a highly thermophilic fungal xylanase and reveals the importance of loop 4 for catalytic efficiency. |
[Mh] Termos MeSH primário: |
Ascomicetos/enzimologia Endo-1,4-beta-Xilanases/metabolismo
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[Mh] Termos MeSH secundário: |
Ascomicetos/genética Catálise Domínio Catalítico Clonagem Molecular Estabilidade Enzimática Proteínas Fúngicas/metabolismo Ligações de Hidrogênio Concentração de Íons de Hidrogênio Hidrólise Cinética Simulação de Dinâmica Molecular Mutagênese Mutagênese Sítio-Dirigida Mutação Pichia/genética Pichia/metabolismo Proteínas Recombinantes/metabolismo Talaromyces/metabolismo Xilanos/metabolismo
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[Pt] Tipo de publicação: | JOURNAL ARTICLE |
[Nm] Nome de substância:
| 0 (Fungal Proteins); 0 (Recombinant Proteins); 0 (Xylans); EC 3.2.1.8 (Endo-1,4-beta Xylanases) |
[Em] Mês de entrada: | 1801 |
[Cu] Atualização por classe: | 180112 |
[Lr] Data última revisão:
| 180112 |
[Sb] Subgrupo de revista: | IM |
[Da] Data de entrada para processamento: | 171219 |
[St] Status: | MEDLINE |
[do] DOI: | 10.1371/journal.pone.0189806 |
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