Caputi Lorenzo, Cianci Michele, Benini Stefano
Laboratory of Bioorganic Chemistry and Crystallography, Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2013 May 1;69(Pt 5):570-3. doi: 10.1107/S1744309113010750. Epub 2013 Apr 30.
The Gram-negative bacterium Erwinia amylovora is a destructive pathogen of Rosaceae. During infection, E. amylovora produces the exopolysaccharide levan, which contributes to the occlusion of plant vessels, causing the wilting of shoots. Levan is a fructose polymer that is synthesized by multifunctional enzymes called levansucrases. The levansucrase from E. amylovora (EaLsc) was heterologously expressed as a GST-fusion protein in Escherichia coli, purified and crystallized after tag removal. The protein crystallized in space group P21212. X-ray diffraction data were acquired to 2.77 Å resolution. The structure of the enzyme was solved by molecular replacement. The asymmetric unit contains eight enzyme molecules, giving a solvent content of 58.74% and a Matthews coefficient of 2.98 Å(3) Da(-1).
革兰氏阴性细菌梨火疫病菌（Erwinia amylovora）是蔷薇科植物的一种毁灭性病原菌。在感染过程中，梨火疫病菌会产生胞外多糖果聚糖，这种多糖会导致植物导管堵塞，从而引起嫩枝枯萎。果聚糖是一种果糖聚合物，由称为果聚糖蔗糖酶的多功能酶合成。来自梨火疫病菌的果聚糖蔗糖酶（EaLsc）在大肠杆菌中作为GST融合蛋白进行异源表达，去除标签后进行纯化和结晶。该蛋白在空间群P21212中结晶。X射线衍射数据采集到2.77 Å分辨率。通过分子置换法解析了该酶的结构。不对称单元包含八个酶分子，溶剂含量为58.74%，马修斯系数为2.98 Å(3) Da(-1)。
