AlkB
双加氧酶
辅因子
DNA
核糖核酸
生物化学
化学
立体化学
大肠杆菌
核酸
酶
DNA修复
生物
基因
作者
Boris Bleijlevens,Tara Shivarattan,Kim S. van den Boom,Annett de Haan,Gert van der Zwan,Peter Simpson,Stephen Matthews
出处
期刊:Biochemistry
[American Chemical Society]
日期:2012-04-09
卷期号:51 (16): 3334-3341
被引量:36
摘要
The Escherichia coli DNA repair enzyme AlkB is a 2-oxoglutarate (2OG)-dependent Fe(2+) binding dioxygenase that removes methyl lesions from DNA and RNA. To date, nine human AlkB homologues are known: ABH1 to ABH8 and the obesity-related FTO. Similar to AlkB, these homologues exert their activity on nucleic acids, although for some homologues the biological substrate remains to be identified. 2OG dioxygenases require binding of the cofactors Fe(2+) and 2OG in the active site to form a catalytically competent complex. We present a structural analysis of AlkB using NMR, fluorescence, and CD spectroscopy to show that AlkB is a dynamic protein exhibiting different folding states. In the absence of the cofactors Fe(2+) and 2OG, apoAlkB is a highly dynamic protein. Binding of either Fe(2+) or 2OG alone does not significantly affect the protein dynamics. Formation of a fully folded and catalytically competent holoAlkB complex only occurs when both 2OG and Fe(2+) are bound. These findings provide the first insights into protein folding of 2OG-dependent dioxygenases. A role for protein dynamics in the incorporation of the metal cofactor is discussed.
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