Benini Stefano, Caputi Lorenzo, Cianci Michele
Laboratory of Bioorganic Chemistry and Bio-Crystallography (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
Biological Chemistry Department, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, England.
Acta Crystallogr F Struct Biol Commun. 2014 Dec 1;70(Pt 12):1693-6. doi: 10.1107/S2053230X14024947. Epub 2014 Nov 28.
The Gram-negative bacterium Erwinia amylovora is a destructive pathogen of plants belonging to the Rosaceae family. Amongst its pathogenicity factors, E. amylovora produces the exopolysaccharide amylovoran, which contributes to the occlusion of plant vessels, causing wilting of shoots and eventually resulting in plant death. Amylovoran biosynthesis requires the presence of 12 genes (from amsA to amsL) clustered in the ams region of the E. amylovora genome. They mostly encode glycosyl transferases (AmsG, AmsB, AmsD, AmsE, AmsJ and AmsK), proteins involved in amylovoran translocation and assembly (AmsH, AmsL and AmsC), and also a tyrosine kinase (AmsA) and a tyrosine phosphatase (AmsI), which are both involved in the regulation of amylovoran biosynthesis. The low-molecular-weight protein tyrosine phosphatase AmsI was overexpressed as a His6-tagged protein in Escherichia coli, purified and crystallized. X-ray diffraction data were collected to a maximum resolution of 1.57 Å in space group P3121.
革兰氏阴性菌梨火疫病菌是蔷薇科植物的一种毁灭性病原菌。在其致病因子中，梨火疫病菌产生胞外多糖淀粉果聚糖，它会导致植物导管堵塞，引起嫩枝枯萎并最终导致植物死亡。淀粉果聚糖的生物合成需要12个基因（从amsA到amsL），它们聚集在梨火疫病菌基因组的ams区域。它们大多编码糖基转移酶（AmsG、AmsB、AmsD、AmsE、AmsJ和AmsK）、参与淀粉果聚糖转运和组装的蛋白质（AmsH、AmsL和AmsC），还有一个酪氨酸激酶（AmsA）和一个酪氨酸磷酸酶（AmsI），二者都参与淀粉果聚糖生物合成的调控。低分子量蛋白质酪氨酸磷酸酶AmsI在大肠杆菌中作为His6标签蛋白过量表达、纯化并结晶。在空间群P3121中收集到了最高分辨率为1.57 Å的X射线衍射数据。
