Richet E, Raibaud O
Unité de Génétique Moléculaire, Institut Pasteur, Paris, France.
EMBO J. 1989 Mar;8(3):981-7. doi: 10.1002/j.1460-2075.1989.tb03461.x.
We show that MalT, the transcriptional activator of the Escherichia coli maltose regulon, specifically binds ATP and dATP with a high affinity (Kd = 0.4 microM) and exhibits a weak ATPase activity. Using an abortive initiation assay, we further show that activation of open complex formation by MalT depends on the presence of ATP in addition to that of maltotriose, the inducer of the maltose system. Similar experiments in which ATP was replaced by ADP or AMP-PNP, a non-hydrolysable analogue of ATP, demonstrate that this reaction does not require ATP hydrolysis. As revealed by DNase I footprinting, both ATP and maltotriose are required for the binding of the MalT protein to the mal promoter DNA.
我们发现，大肠杆菌麦芽糖操纵子的转录激活因子MalT能以高亲和力（Kd = 0.4 microM）特异性结合ATP和dATP，并表现出微弱的ATP酶活性。通过流产起始试验，我们进一步表明，除麦芽糖系统的诱导物麦芽三糖外，MalT对开放复合物形成的激活还依赖于ATP的存在。用ADP或ATP的非水解类似物AMP-PNP替代ATP的类似实验表明，该反应不需要ATP水解。DNase I足迹实验显示，ATP和麦芽三糖都是MalT蛋白与mal启动子DNA结合所必需的。
