Yang Teng, Liu Tingting, Gan Jianhua, Yu Kunqian, Chen Kaixian, Xue Wei, Lan Lefu, Yang Song, Yang Cai-Guang
State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals , Guizhou University , 2708 South Huaxi Road , Guiyang , Guizhou 550025 , P. R. China.
State Key Laboratory of Drug Research , Shanghai Institute of Materia Medica, Chinese Academy of Sciences , 555 Zuchongzhi Road , Shanghai 201203 , P. R. China.
ACS Infect Dis. 2019 Jun 14;5(6):841-850. doi: 10.1021/acsinfecdis.8b00316. Epub 2019 Mar 25.
Staphylococcus aureus Stp1, which belongs to the bacterial metal-dependent protein phosphatase (PPM) family, is a promising candidate for antivirulence targeting. How Stp1 recognizes the phosphorylated peptide remains unclear, however. In order to investigate the recognition mechanism of Stp1 in depth, we have determined a series of crystal structures of S. aureus Stp1 in different states and the structural complex of Stp1 bound with a phosphorylated peptide His12. Different phosphorylated peptides, including MgrA- and GraR-derived phosphopeptides, are substrates of Stp1, which supports the function of Stp1 as a selective Ser/Thr phosphatase. In addition, interestingly, the crystal structures of R161-Stp1 variants combined with the biochemical activity validations have uncovered that R161 residue plays a key role to control the conformation switches of the flap domain in order to facilitate substrate binding and the dephosphorylation process. Our findings provide crucial structural insight into the molecular mechanism of S. aureus Stp1 phosphatase and reveal the phosphorylated peptides for biochemistry study and inhibitor screening of Stp1.
金黄色葡萄球菌Stp1属于细菌金属依赖性蛋白磷酸酶（PPM）家族，是抗毒力靶向治疗的一个有前景的候选物。然而，Stp1如何识别磷酸化肽仍不清楚。为了深入研究Stp1的识别机制，我们测定了金黄色葡萄球菌Stp1在不同状态下的一系列晶体结构以及Stp1与磷酸化肽His12结合的结构复合物。包括MgrA和GraR衍生的磷酸肽在内的不同磷酸化肽都是Stp1的底物，这支持了Stp1作为选择性丝氨酸/苏氨酸磷酸酶的功能。此外，有趣的是，R161-Stp1变体的晶体结构与生化活性验证相结合，揭示了R161残基在控制瓣状结构域的构象转换中起关键作用，以促进底物结合和去磷酸化过程。我们的研究结果为金黄色葡萄球菌Stp1磷酸酶的分子机制提供了关键的结构见解，并揭示了用于Stp1生物化学研究和抑制剂筛选的磷酸化肽。
