The allosteric role of the AAA+ domain of ChlD protein from the magnesium chelatase of synechocystis species PCC 6803.
The allosteric role of the AAA+ domain of ChlD protein from the magnesium chelatase of synechocystis species PCC 6803.
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DOI：
10.1074/jbc.m113.477943
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发表时间：
2013-10-04
期刊：
影响因子：
--
通讯作者：
Reid JD
中科院分区：
文献类型：
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作者：
Adams NB;Reid JD
背景：镁螯合酶催化叶绿素生物合成的第一个重要步骤。结果：镁螯合酶ChlD亚基的AAA+结构域中的突变降低但不消除催化活性。结论：ChlD是镁螯合酶的变构调节剂。意义：这些观察揭示了叶绿素D蛋白在叶绿素生物合成的第一个承诺阶段中的重要作用。镁螯合酶是一种AAA+ ATP酶，催化叶绿素生物合成的第一步，即镁离子插入卟啉环的能量不利插入。该酶含有两个AAA+结构域，一个在ChlI蛋白中有活性，一个在ChlD蛋白中无活性。使用ChlD的AAA+结构域中的一系列突变体，我们表明该位点对于镁螯合和变构调节Mg2+和MgATP 2 −结合是必不可少的。
Background: Magnesium chelatase catalyzes the first essential step in chlorophyll biosynthesis. Results: Mutations in the AAA+ domain of the magnesium chelatase ChlD subunit reduce but do not abolish catalytic activity. Conclusion: ChlD is an allosteric regulator of magnesium chelatase. Significance: These observations reveal an essential role for the ChlD protein in the first committed stage in chlorophyll biosynthesis. Magnesium chelatase is an AAA+ ATPase that catalyzes the first step in chlorophyll biosynthesis, the energetically unfavorable insertion of a magnesium ion into a porphyrin ring. This enzyme contains two AAA+ domains, one active in the ChlI protein and one inactive in the ChlD protein. Using a series of mutants in the AAA+ domain of ChlD, we show that this site is essential for magnesium chelation and allosterically regulates Mg2+ and MgATP2− binding.