Novel essential residues of Hda for interaction with DnaA in the regulatory inactivation of DnaA: Unique roles for Hda AAA+ Box VI and VII motifs.
Novel essential residues of Hda for interaction with DnaA in the regulatory inactivation of DnaA: Unique roles for Hda AAA+ Box VI and VII motifs.
复制标题
在 DnaA 调控失活中与 DnaA 相互作用的 Hda 新型必需残基：Hda AAA Box VI 和 VII 基序的独特作用。
DOI：
10.1111/j.1365-2958.2010.07074.x
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
T.
中科院分区：
文献类型：
--
作者：
Nakamura;K. and Katayama;T.
大肠杆菌- dna启动染色体复制。为了防止额外起始，ADP-Hda复合物和DNA负载复制酶钳促进DnaA - ATP水解，产生无活性ADP-DnaA。然而，除了每个AAA+结构域内的Hda Box VII Arg finger （Arg‐153）和DnaA sensor II Arg‐334对DnaA‐ATP水解至关重要外，Hda - DnaA相互作用模式尚不清楚。在这里，我们证明了ADP-Hda与dna的直接和功能性相互作用需要Hda残基Ser‐152、Phe‐118和Asn‐122，以及Hda Arg‐153和DnaA Arg‐334。结构分析表明Hda Ser - 152和dna Arg - 334之间、Hda Phe - 118和dna Walker B基序区域之间存在分子间相互作用，此外Hda Asn - 122和Arg - 153之间也存在分子内相互作用。这些相互作用可能维持ADP-Hda和DnaA的特定关联，促进DnaA - ATP水解。一致地，atp - dna和adp - dna与ADP-Hda - dna夹紧复合物的相互作用具有相似的亲和力。Hda Phe‐118和Asn‐122包含在Box VI区域，它们的疏水和静电特性在其他AAA+蛋白的相应残基中基本保守，表明Box VI具有保守作用。这些发现表明Hda - dnaa的新相互作用机制以及AAA+蛋白相互作用的潜在基础机制。
Escherichia coliATP–DnaA initiates chromosomal replication. For preventing extra‐initiations, a complex of ADP–Hda and the DNA‐loaded replicase clamp promotes DnaA‐ATP hydrolysis, yielding inactive ADP–DnaA. However, the Hda–DnaA interaction mode remains unclear except that the Hda Box VII Arg finger (Arg‐153) and DnaA sensor II Arg‐334 within each AAA+domain are crucial for the DnaA‐ATP hydrolysis. Here, we demonstrate that direct and functional interaction of ADP–Hda with DnaA requires the Hda residues Ser‐152, Phe‐118 and Asn‐122 as well as Hda Arg‐153 and DnaA Arg‐334. Structural analyses suggest intermolecular interactions between Hda Ser‐152 and DnaA Arg‐334 and between Hda Phe‐118 and the DnaA Walker B motif region, in addition to an intramolecular interaction between Hda Asn‐122 and Arg‐153. These interactions likely sustain a specific association of ADP–Hda and DnaA, promoting DnaA‐ATP hydrolysis. Consistently, ATP–DnaA and ADP–DnaA interact with the ADP–Hda‐DNA–clamp complex with similar affinities. Hda Phe‐118 and Asn‐122 are contained in the Box VI region, and their hydrophobic and electrostatic features are basically conserved in the corresponding residues of other AAA+proteins, suggesting a conserved role for Box VI. These findings indicate novel interaction mechanisms for Hda–DnaA as well as a potentially fundamental mechanism in AAA+protein interactions.