Deochand D K, Perera I C, Crochet R B, Gilbert N C, Newcomer M E, Grove A
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Mol Biosyst. 2016 Jul 19;12(8):2417-26. doi: 10.1039/c6mb00304d.
Therapeutic strategies have been reported that depend on synthetic network devices in which a urate-sensing transcriptional regulator detects pathological levels of urate and triggers production or release of urate oxidase. The transcription factor involved, HucR, is a member of the multiple antibiotic resistance (MarR) protein family. We show that protonation of stacked histidine residues at the pivot point of long helices that form the scaffold of the dimer interface leads to reversible formation of a molten globule state and significantly attenuated DNA binding at physiological temperatures. We also show that binding of urate to symmetrical sites in each protein lobe is communicated via the dimer interface. This is the first demonstration of regulation of a MarR family transcription factor by pH-dependent interconversion between a molten globule and a compact folded state. Our data further suggest that HucR may be utilized in synthetic devices that depend on detection of pH changes.
据报道，治疗策略依赖于合成网络装置，其中尿酸感应转录调节因子可检测尿酸的病理水平并触发尿酸氧化酶的产生或释放。所涉及的转录因子HucR是多重抗生素抗性（MarR）蛋白家族的成员。我们发现，形成二聚体界面支架的长螺旋枢纽点处堆积的组氨酸残基的质子化导致熔球态的可逆形成，并在生理温度下显著减弱DNA结合。我们还表明，尿酸与每个蛋白叶中对称位点的结合是通过二聚体界面传递的。这是首次证明MarR家族转录因子通过熔球态和紧密折叠态之间的pH依赖性相互转换进行调节。我们的数据进一步表明，HucR可用于依赖于检测pH变化的合成装置中。
