Crystallographic Studies of Polyphosphate Kinase

聚磷酸盐(Poly(P))是由数百个正磷酸盐(PI)残基通过以下键连接而成的线性聚合物 高能的磷酸酸酐键。许多证据表明，聚(P)在 对压力和营养不足的监管反应。多聚磷酸酶(PPK)是一种 负责从三磷酸腺苷可逆合成聚(P)。最近有证据表明，PPK是必不可少的 对于生物膜的发育、群体感应、运动和释放多种致病菌的毒力因子 微生物，包括铜绿假单胞菌。PPK基因敲除导致PPK细胞活力丧失 病原微生物。因此，PPK特异性抑制剂可能成为一类新的抗生素家族，其 对克服囊性纤维化和其他免疫缺陷患者的抗生素耐药性非常有用，以及 可以在打击生物恐怖主义方面发挥作用。 PPK是一种膜相关酶，与其他酶没有明显的序列同源性 蛋白质。PPK系列没有可用的三维结构信息。我们最近做了 纯化和结晶全长的大肠杆菌PPK，并用X-射线衍射仪测定其结构的初始相。 得到了射线结晶学结果。这项建议的主要目的是测定晶体 PPK及其与不同底物和反应中间体的络合物的结构。我们的结构 研究将有助于确定PPK的催化机制，并为药物设计提供见解。 城市、州)

Polyphosphate (poly(P)) is a linear polymer of hundreds of orthophosphate (Pi) residues linked by high-energy phosphoanhydride bonds. Many lines of evidence indicate that poly(P) plays a critical role in regulatory responses to stresses and nutritional deficiencies. Polyphosphate kinase (PPK) is an enzyme responsible for the reversible synthesis of poly(P) from ATP. It has been shown recently that PPK is essential for biofilm development, quorum sensing, motility and release of virulence factors of many pathogenic microorganisms, including P. aeruginosa. Knockout of the PPK gene leads to the loss of viability of the pathogenic microorganism. Thus PPK specific inhibitors could become a novel family of antibiotics, which can be very useful to overcome antibiotic resistance in cystic fibrosis and other immunodeficient patients, and could play a role in combating bioterrorism. PPK is a membrane-associated enzyme that does not have apparent sequence homology with other proteins. No three-dimensional structural information is available for the PPK family. We have recently purified and crystallized the full-length E. coli PPK, and the initial phases for structure determination by X- ray crystallography have been obtained. The main goal of this proposal is the determination of crystal structures of PPK and its complexes with various substrates and reaction intermediate mimics. Our structural studies will aid in determining the PPK catalytic mechanism and provide insights into drug design. city, state)