Mechanistic Investigations of Anaerobic Sulfatase-Maturating Enzyme: Direct Cβ H-Atom Abstraction Catalyzed by a Radical AdoMet Enzyme
Mechanistic Investigations of Anaerobic Sulfatase-Maturating Enzyme: Direct Cβ H-Atom Abstraction Catalyzed by a Radical AdoMet Enzyme
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DOI：
10.1021/ja901571p
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发表时间：
2009-06-24
影响因子：
15
通讯作者：
Berteau, Olivier
中科院分区：
文献类型：
--
作者：
Benjdia, Alhosna;Leprince, Jerome;Berteau, Olivier
磺化酶的独特之处在于需要对关键活性位点半胱氨酸或丝氨酸残基进行必要的翻译后修饰，使其成为3-氧丙氨酸，通常称为C α -甲酰基甘氨酸（FGly）。这种翻译后修饰是由厌氧硫酸盐酶成熟酶（anSME）催化的，anSME是AdoMet超家族的一员。使用新的标记底物，我们证明了anSME使用5'-脱氧腺苷基来催化从底物中直接提取h原子。因此，我们确定ansme是第一个催化翻译后修饰的AdoMet自由基酶，涉及从活性位点半胱氨酸或丝氨酸残基中提取C， h原子。这项机制研究使我们能够破译这种新的自由基AdoMet酶家族机制的第一步。
Sulfatases are unique in requiring an essential post-translational modification of a critical active-site cysteinyt or seryl residue to 3-oxoalanine usually called C alpha-formylglycine (FGly). This post-translational modification is catalyzed anaerobically by anaerobic Sulfatase Maturating Enzyme (anSME), a member of the radical AdoMet superfamily. Using a new labeled substrate, we demonstrate that anSME uses a 5'-deoxyadenosyl radical to catalyze direct H-atom abstraction from the substrate. We thus established that anSMEs are the first radical AdoMet enzymes catalyzing a post-translational modification involving C, H-atom abstraction from an active site cysteinyl or seryl residue. This mechanistic study allowed us to decipher the first steps of the mechanism of this new radical AdoMet enzyme family.