The solution structure of the regulatory domain of tyrosine hydroxylase.
The solution structure of the regulatory domain of tyrosine hydroxylase.
复制标题
酪氨酸羟化酶调节域的溶液结构。
DOI：
10.1016/j.jmb.2013.12.015
复制
发表时间：
2014
影响因子：
5.6
通讯作者：
Fitzpatrick,PaulF
中科院分区：
文献类型：
--
作者：
Zhang,Shengnan;Huang,Tao;Ilangovan,Udayar;Hinck,AndrewP;Fitzpatrick,PaulF
酪氨酸羟化酶（TyrH）在儿茶酚胺类神经递质的生物合成中催化酪氨酸羟基化形成3，4-二羟基苯丙氨酸。该酶的活性通过调节结构域中丝氨酸残基的磷酸化和通过儿茶酚胺与活性位点的结合来调节。TyrH的可用结构缺乏调节结构域，限制了对结构调节作用的理解。我们报告使用核磁共振光谱分析的解决方案结构的隔离调节结构域的大鼠TyrH。该蛋白由一个大部分非结构化的N-末端区域（残基1-71）和一个折叠良好的C-末端部分（残基72-159）组成。含有残基65-159的调节结构域的截短形式的结构已被确定，并确定其为ACT结构域。分离的结构域在溶液中是同源二聚体，每个单体的结构与苯丙氨酸羟化酶的调节结构域的核心非常相似。两个TyrH调节结构域单体形成ACT结构域二聚体，该二聚体由八条链的片层组成，片层的一侧有四个α螺旋。进行骨架动态分析以表征TyrH 65 -159的构象柔性。这些结果为了解TyrH的调控机制提供了重要的分子细节。
Tyrosine hydroxylase (TyrH) catalyzes the hydroxylation of tyrosine to form 3,4-dihydroxyphenylalanine in the biosynthesis of the catecholamine neurotransmitters. The activity of the enzyme is regulated by phosphorylation of serine residues in a regulatory domain and by binding of catecholamines to the active site. Available structures of TyrH lack the regulatory domain, limiting the understanding of the effect of regulation on structure. We report the use of NMR spectroscopy to analyze the solution structure of the isolated regulatory domain of rat TyrH. The protein is composed of a largely unstructured N-terminal region (residues 1–71) and a well-folded C-terminal portion (residues 72–159). The structure of a truncated version of the regulatory domain containing residues 65–159 has been determined and establishes that it is an ACT domain. The isolated domain is a homodimer in solution, with the structure of each monomer very similar to that of the core of the regulatory domain of phenylalanine hydroxylase. Two TyrH regulatory domain monomers form an ACT domain dimer composed of a sheet of eight strands with four α-helices on one side of the sheet. Backbone dynamic analyses were carried out to characterize the conformational flexibility of TyrH65–159. The results provide molecular details critical for understanding the regulatory mechanism of TyrH.