Diogo José Alberto, Zanphorlin Leticia Maria, Sato Hélia Harumi, Murakami Mario Tyago, Ruller Roberto
Brazilian Bioethanol Science and Technology Laboratory (CTBE), National Center for Research in Energy and Materials (CNPEM), Giuseppe Maximo Scolfaro 10000, 13083-100 Campinas-SP, Brazil.
Department of Food Science, University of Campinas, Rua Monteiro Lobato 80, Cidade Universitária, 13081-970 Campinas-SP, Brazil.
Acta Crystallogr F Struct Biol Commun. 2015 Aug;71(Pt 8):962-5. doi: 10.1107/S2053230X15009978. Epub 2015 Jul 28.
β-Xylosidases (EC 3.2.1.37) catalyze the hydrolysis of short xylooligosaccharides into xylose, which is an essential step in the complete depolymerization of xylan, the major hemicellulosic polysaccharide of plant cell walls, and has great biotechnological relevance for the production of lignocellulose-based biofuels and the paper industry. In this study, a GH43 β-xylosidase identified from the bacterium Bacillus licheniformis (BlXylA) was cloned into the the pET-28a bacterial expression vector, recombinantly overexpressed in Escherichia coli BL21(DE3) cells and purified to homogeneity by metal-affinity and size-exclusion chromatography. The protein was crystallized in the presence of the organic solvent 2-methyl-2,4-pentanediol and a single crystal diffracted to 2.49 Å resolution. The X-ray diffraction data were indexed in the monoclinic space group C2, with unit-cell parameters a = 152.82, b = 41.9, c = 71.79 Å, β = 91.7°. Structural characterization of this enzyme will contribute to a better understanding of the structural requirements for xylooligosaccharide specificity within the GH43 family.
β-木糖苷酶（EC 3.2.1.37）催化短链木寡糖水解为木糖，这是木聚糖完全解聚过程中的关键步骤，木聚糖是植物细胞壁中主要的半纤维素多糖，对于木质纤维素基生物燃料的生产和造纸工业具有重要的生物技术意义。在本研究中，从地衣芽孢杆菌中鉴定出的一种GH43 β-木糖苷酶（BlXylA）被克隆到pET-28a细菌表达载体中，在大肠杆菌BL21(DE3)细胞中进行重组过表达，并通过金属亲和色谱和尺寸排阻色谱纯化至均一。该蛋白在有机溶剂2-甲基-2,4-戊二醇存在下结晶，单晶衍射分辨率达到2.49 Å。X射线衍射数据在单斜晶系空间群C2中指标化，晶胞参数为a = 152.82、b = 41.9、c = 71.79 Å，β = 91.7°。该酶的结构表征将有助于更好地理解GH43家族中木寡糖特异性的结构要求。
