Salomone-Stagni Marco, Zambelli Barbara, Musiani Francesco, Ciurli Stefano
Laboratory of Bioinorganic Chemistry, Department of Agro-Environmental Science and Technology, University of Bologna, I-40127 Bologna, Italy.
Proteins. 2007 Aug 15;68(3):749-61. doi: 10.1002/prot.21472.
UreF is a protein that plays a role in the in vivo urease activation as a chaperone involved in the insertion of two Ni(2+) ions in the apo-urease active site. The molecular details of this process are unknown. In the absence of any molecular information on the UreF protein class, and as a step toward the comprehension of the relationships between UreF function and structure, we applied a structural modeling approach to infer useful biochemical knowledge on Bacillus pasteurii UreF (BpUreF). Similarity searches and multiple alignment of UreF protein sequences indicated that this class of proteins has a low homology with proteins of known structure. Fold recognition methods were therefore used to identify useful protein structural templates to model the structure of BpUreF. In particular, the templates belong to the class of GTPase-activating proteins. Modeling of BpUreF based on these templates was performed using the program MODELLER. The structure validation yielded good statistics, indicating that the model is plausible. This result suggests a role for UreF in urease active site biosynthesis as a regulator of the activity of UreG, a small G protein involved in the in vivo apo-urease activation process and established to catalyze GTP hydrolysis.
脲酶激活因子（UreF）是一种蛋白质，作为伴侣蛋白在体内脲酶激活过程中发挥作用，参与将两个镍离子插入脱辅基脲酶活性位点。该过程的分子细节尚不清楚。由于缺乏关于脲酶激活因子（UreF）蛋白类别的任何分子信息，作为理解UreF功能与结构之间关系的第一步，我们应用结构建模方法来推断巴氏芽孢杆菌UreF（BpUreF）的有用生化知识。UreF蛋白序列的相似性搜索和多序列比对表明，这类蛋白质与已知结构的蛋白质具有较低的同源性。因此，采用折叠识别方法来识别有用的蛋白质结构模板，以对BpUreF的结构进行建模。特别是，这些模板属于GTP酶激活蛋白类别。基于这些模板，使用MODELLER程序对BpUreF进行建模。结构验证产生了良好的统计结果，表明该模型是合理的。这一结果表明，UreF在脲酶活性位点生物合成中作为UreG活性的调节剂发挥作用，UreG是一种参与体内脱辅基脲酶激活过程并已确定可催化GTP水解的小G蛋白。
