Function and structure of a prokaryotic formylglycine-generating enzyme.
Function and structure of a prokaryotic formylglycine-generating enzyme.
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DOI：
10.1074/jbc.m800217200
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发表时间：
2008-07-18
期刊：
影响因子：
--
通讯作者：
Bertozzi CR
中科院分区：
文献类型：
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作者：
Carlson BL;Ballister ER;Skordalakes E;King DS;Breidenbach MA;Gilmore SA;Berger JM;Bertozzi CR
I型硫酸酯酶在水解硫酸酯中的活性需要不寻常的共翻译或翻译后修饰。在真核生物硫酸酯酶中，活性位点半胱氨酸残基被甲酰甘氨酸生成酶（FGE）氧化为含谷胱甘肽的Cα-甲酰甘氨酸残基。原核生物中负责硫酸酯酶激活的机制知之甚少。在这里，我们描述了从结核分枝杆菌的原核FGE的鉴定。此外，我们还解析了天蓝色链霉菌FGE同系物的晶体结构，分辨率达到2.1 nm。原核同源物表现出与人FGE显著的结构相似性，包括催化半胱氨酸残基的位置。生物化学和结构数据都表明，在活性部位存在氧化半胱氨酸修饰，这可能与催化作用有关。此外，我们还产生了一个突变体M。缺乏FGE的结核菌株。虽然全球硫酸酯酶活性降低的突变体，大量的残留硫酸酯酶活性表明存在的FGE-独立的硫酸酯酶在这种生物体。
Type I sulfatases require an unusual co- or post-translational modification for their activity in hydrolyzing sulfate esters. In eukaryotic sulfatases, an active site cysteine residue is oxidized to the aldehyde-containing Cα-formylglycine residue by the formylglycine-generating enzyme (FGE). The machinery responsible for sulfatase activation is poorly understood in prokaryotes. Here we describe the identification of a prokaryotic FGE from Mycobacterium tuberculosis. In addition, we solved the crystal structure of the Streptomyces coelicolor FGE homolog to 2.1Å resolution. The prokaryotic homolog exhibits remarkable structural similarity to human FGE, including the position of catalytic cysteine residues. Both biochemical and structural data indicate the presence of an oxidized cysteine modification in the active site that may be relevant to catalysis. In addition, we generated a mutant M. tuberculosis strain lacking FGE. Although global sulfatase activity was reduced in the mutant, a significant amount of residual sulfatase activity suggests the presence of FGE-independent sulfatases in this organism.