Kelly Leanne, McDonough Michael A, Coleman Mathew L, Ratcliffe Peter J, Schofield Christopher J
The Chemistry Research Laboratory and Oxford Centre for Integrative Systems Biology, University of Oxford, Oxford, UKOX1 3TA.
Mol Biosyst. 2009 Jan;5(1):52-8. doi: 10.1039/b815271c. Epub 2008 Oct 29.
Ankyrin repeats (ARs) are one of the most common structural motifs among eukaryotic proteins. Recent analyses have shown that factor inhibiting hypoxia-inducible factor (FIH) catalyses the hydroxylation of highly conserved Asn-residues within ankyrin repeat domains (ARDs). However, the effect of Asn-hydroxylation on ARD structure is unknown. Supporting the proposal that FIH-mediated ARD hydroxylation is ubiquitous we report that consensus ARD proteins are FIH substrates both in vitro and in vivo. X-ray diffraction analyses revealed that hydroxylation does not alter the archetypical ARD conformation in the crystalline state. However, other biophysical analyses revealed that hydroxylation significantly stabilizes the ARD fold in solution. We propose that intracellular protein hydroxylation is much more common than previously thought and that one of its roles is stabilization of localized regions of ARD folds.
锚蛋白重复序列（ARs）是真核生物蛋白质中最常见的结构基序之一。最近的分析表明，缺氧诱导因子抑制因子（FIH）催化锚蛋白重复结构域（ARDs）内高度保守的天冬酰胺残基的羟基化。然而，天冬酰胺羟基化对ARD结构的影响尚不清楚。为支持FIH介导的ARD羟基化普遍存在这一观点，我们报告称，共有ARD蛋白在体外和体内都是FIH的底物。X射线衍射分析表明，羟基化在晶体状态下不会改变典型的ARD构象。然而，其他生物物理分析表明，羟基化显著稳定了溶液中ARD的折叠。我们认为，细胞内蛋白质羟基化比以前认为的更为普遍，其作用之一是稳定ARD折叠的局部区域。
