Structure of the Escherichia coli phosphonate binding protein PhnD and rationally optimized phosphonate biosensors.
Structure of the Escherichia coli phosphonate binding protein PhnD and rationally optimized phosphonate biosensors.
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DOI：
10.1016/j.jmb.2011.09.047
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发表时间：
2011-12-02
影响因子：
5.6
通讯作者：
Schreiter ER
中科院分区：
文献类型：
--
作者：
Alicea I;Marvin JS;Miklos AE;Ellington AD;Looger LL;Schreiter ER
大肠杆菌的phnD基因编码磷酸盐摄取和利用途径的周质结合蛋白。对E.大肠杆菌PhnD（EcPhnD）在缺乏配体的情况下与环境丰富的2-氨基乙基膦酸酯（2AEP）复合。与其他细菌周质结合蛋白类似，2AEP在两个叶之间形成的裂缝中的EcPhnD的质心附近结合。开放的未配体结构与闭合的2AEP结合结构的比较表明，两个叶在两种状态之间围绕铰链枢转约70°。广泛的氢键和静电相互作用稳定2AEP，其以低纳摩尔亲和力结合到EcPhnD。这些结构提供了深入了解膦酸盐摄取细菌和促进高信噪比的膦酸盐生物传感器的耦合小分子染料和自催化荧光蛋白的基础上的合理设计。
The phnD gene of Escherichia coli encodes the periplasmic binding protein of the phosphonate uptake and utilization pathway. We have crystallized and determined structures of E. coli PhnD (EcPhnD) in the absence of ligand and in complex with the environmentally abundant 2-aminoethylphosphonate (2AEP). Similar to other bacterial periplasmic binding proteins, 2AEP binds near the center of mass of EcPhnD in a cleft formed between two lobes. Comparison of the open, unliganded structure with the closed 2AEP-bound structure shows that the two lobes pivot around a hinge by ~70° between the two states. Extensive hydrogen bonding and electrostatic interactions stabilize 2AEP, which binds to EcPhnD with low nanomolar affinity. These structures provide insight into phosphonate uptake by bacteria and facilitated the rational design of high signal-to-noise phosphonate biosensors based both on coupled small molecule dyes and autocatalytic fluorescent proteins.