Structure of factor-inhibiting hypoxia-inducible factor (HIF) reveals mechanism of oxidative modification of HIF-1α
Structure of factor-inhibiting hypoxia-inducible factor (HIF) reveals mechanism of oxidative modification of HIF-1α
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DOI：
10.1074/jbc.c200644200
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发表时间：
2003-01-17
影响因子：
4.8
通讯作者：
Schofield, CJ
中科院分区：
文献类型：
--
作者：
Elkins, JM;Hewitson, KS;Schofield, CJ
缺氧诱导因子（HIF）的活性受氧依赖性羟基化的调节。在常氧条件下，脯氨酸残基的羟基化引发其α-亚基的破坏，而HIF-1 α（CAD）的C-末端反式激活结构域中的Asn（803）的羟基化阻止其与p300的相互作用。在这里，我们报告晶体结构的天冬酰胺羟化酶（因子抑制HIF，FIH）与铁（II），2-酮戊二酸共底物，CAD片段，这揭示了HIF修改的结构基础。CAD结合FIH发生通过诱导拟合过程在两个不同的相互作用位点。在羟基化位点，CAD采用环状构象，与结合到p300时相同残基的螺旋构象形成对比。CAD的Asn（803）被埋在活性位点中并精确定向，使得羟基化发生在其β-碳上。与抑制剂Zn-（II）和N-草酰甘氨酸的结构一起，FIH-CAD复合物的分析将有助于设计具有促血管生成特性的羟化酶抑制剂。FIH内保守的结构基序意味着它是参与基因调控的Fe-（II）加氧酶的扩展家族之一。
The activity of the transcription factor hypoxia-inducible factor (HIF) is regulated by oxygen-dependent hydroxylation. Under normoxic conditions, hydroxylation of proline residues triggers destruction of its a-subunit while hydroxylation of Asn(803) in the C-terminal transactivation domain of HIF-1alpha (CAD) prevents its interaction with p300. Here we report crystal structures of the asparagine hydroxylase (factor-inhibiting HIF, FIH) complexed with Fe-(II), 2-oxoglutarate cosubstrate, and CAD fragments, which reveal the structural basis of HIF modification. CAD binding to FIH occurs via an induced fit process at two distinct interaction sites. At the hydroxylation site CAD adopts a loop conformation, contrasting with a helical conformation for the same residues when bound to p300. Asn(803) of CAD is buried and precisely orientated in the active site such that hydroxylation occurs at its beta-carbon. Together with structures with the inhibitors Zn-(II) and N-oxaloylglycine, analysis of the FIH-CAD complexes will assist design of hydroxylase inhibitors with proangiogenic properties. Conserved structural motifs within FIH imply it is one of an extended family of Fe-(II) oxygenases involved in gene regulation.