The 2.0-A resolution structure of Escherichia coli histidine-containing phosphocarrier protein HPr. A redetermination.
The 2.0-A resolution structure of Escherichia coli histidine-containing phosphocarrier protein HPr. A redetermination.
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大肠杆菌含组氨酸磷酸载体蛋白 HPr 的 2.0-A 分辨率结构。
DOI：
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发表时间：
1994
影响因子：
4.8
通讯作者：
L. Delbaere
中科院分区：
文献类型：
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作者：
Zongchao Jia;J. Quail;E. Waygood;L. Delbaere
大肠杆菌HPr的X射线结构已重新确定为2.0-A分辨率。与先前的研究（El-Kabbani，O. A. L.，Waygood，E. B.，和Delbaere，L. T. J.（1987）J.Biol.Chem.262，12926-12929），总体结构一般类似于其它报道的NMR和x-射线HPr结构，尽管在细节上存在一些重要的差异。HPr的整体折叠拓扑结构是经典的开放式β-三明治结构，由四条反平行的β-链和三条α-螺旋组成。最小二乘细化产生的R指数为0.135的所有测量的独特的数据之间的8.0和2.0 A的分辨率。活性中心由与硫酸根阴离子氢键结合的His 15和具有完全开放构象的Arg 17组成。这对应于HPr活性中心的第一个观察到的“半封闭”构象。粪链球菌HPr结构（Jia，Z.，Vandonselaar，M.，鹌鹑，J.W.，和Delbaere，L. T. J.（1993）Nature 361，94-97）具有“开放”构象，其中His 15和Arg 17的侧链彼此尽可能远离。枯草芽孢杆菌HPr（Herzberg，O.，雷迪，P.，Sutrina，S.，Saier，M. H、小的，Reizer，J.，和Kapadia，G.等人（1992）Proc. Acad. Sci. U.S.A.89，2499-2503）具有“闭合”构象，其中His 15和Arg 17的侧链与位于活性中心的硫酸根阴离子靠近在一起。开放构象代表HPr的非磷酸化形式，而闭合构象可能类似于HPr的磷酸化形式。在E. coli HPr结构可能代表了HPr磷酸化/去磷酸化途径的结构中间体。
The x-ray structure of Escherichia coli HPr has been redetermined at 2.0-A resolution. In contrast to the previous study (El-Kabbani, O. A. L., Waygood, E. B., and Delbaere, L. T. J. (1987) J. Biol. Chem. 262, 12926-12929), the overall structure is, in general, similar to other reported NMR and x-ray HPr structures, although there are some important differences in detail. The overall folding topology of HPr is a classical open-faced beta-sandwich, consisting of four antiparallel beta-strands and three alpha-helices. The least square refinement produced an R index of 0.135 for all measured unique data between 8.0 and 2.0 A resolution. The active center consists of His15 which is hydrogen bonded to a sulfate anion, and Arg17 which has a fully open conformation. This corresponds to the first observed "semi-closed" conformation of the active center of HPr. The Streptococcus faecalis HPr structure (Jia, Z., Vandonselaar, M., Quail, J. W., and Delbaere, L. T. J. (1993) Nature 361, 94-97) has the "open" conformation in which the side chains of His15 and Arg17 are directed as far away from each other as possible. The Bacillus subtilis HPr (Herzberg, O., Reddy, P., Sutrina, S., Saier, M. H., Jr., Reizer, J., and Kapadia, G. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 2499-2503) has the "closed" conformation in which the side chains of His15 and Arg17 are close together with a sulfate anion located in the active center. The open conformation represents the unphosphorylated form of HPr whereas the closed conformation likely resembles the phosphorylated form of HPr. The semi-closed conformation observed in the E. coli HPr structure could represent a structural intermediate on the phosphorylation/dephosphorylation pathway of HPr.