Structure of Streptococcus agalactiae serine/threonine phosphatase -: The subdomain conformation is coupled to the binding of a third metal ion
Structure of Streptococcus agalactiae serine/threonine phosphatase -: The subdomain conformation is coupled to the binding of a third metal ion
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DOI：
10.1111/j.1742-4658.2007.05845.x
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发表时间：
2007-07-01
期刊：
影响因子：
5.4
通讯作者：
Goldman, Adrian
中科院分区：
文献类型：
--
作者：
Rantanen, Mika K.;Lehtio, Lari;Goldman, Adrian
我们解决了无乳链球菌丝氨酸/苏氨酸磷酸酶（SaSTP）的晶体结构，使用单波长反常色散定相和分子置换相结合。整体结构类似于先前表征的PPM/PP 2C STP系列成员。不对称单元包含四个单体，我们观察到两个新的构象的皮瓣域其中。在其中一种构象中，酶结合三种金属离子，而在另一种构象中，它只结合两种。三金属离子结构还具有新颖构象的活性位点精氨酸。两个和三个金属离子结构之间的切换似乎是另一个单体结合到STP的活性位点，这促进了第三个金属离子的结合。这种相互作用可以模拟产物复合物的结合，特别是因为与活性位点结合的基序含有与人STP结构中发现的磷酸盐非常好地对齐的丝氨酸残基。
We solved the crystal structure of Streptococcus agalactiae serine/threonine phosphatase (SaSTP) using a combination of single-wavelength anomalous dispersion phasing and molecular replacement. The overall structure resembles that of previously characterized members of the PPM/PP2C STP family. The asymmetric unit contains four monomers and we observed two novel conformations for the flap domain among them. In one of these conformations, the enzyme binds three metal ions, whereas in the other it binds only two. The three-metal ion structure also has the active site arginine in a novel conformation. The switch between the two- and three-metal ion structures appears to be binding of another monomer to the active site of STP, which promotes binding of the third metal ion. This interaction may mimic the binding of a product complex, especially since the motif binding to the active site contains a serine residue aligning remarkably well with the phosphate found in the human STP structure.