The ACT domain family
The ACT domain family
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DOI：
10.1016/s0959-440x(01)00272-x
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发表时间：
2001-12-01
影响因子：
6.8
通讯作者：
Shaanan, B
中科院分区：
文献类型：
--
作者：
Chipman, DM;Shaanan, B
最近通过PSI-BLAST搜索发现了一个新的配体结合结构域，命名为‘ACT结构域。典型的ACT结构域是3-磷酸甘油酸脱氢酶(3PGDH)的C-末端调节域，它以铁氧还蛋白样β-β拓扑折叠。一对ACT结构域形成一个八链反平行的片状结构，两个变构抑制剂丝氨酸分子结合在界面上。ACT结构域存在于多种环境中，被认为是一个保守的调节性配体结合折叠。大鼠苯丙氨酸羟基酶的调控结构域具有相似的折叠，但不同的配基结合模式。一些未知结构的蛋白质(如乙酰羟酸合成酶调节亚基)中可能的ACT结构域也可能与3PGDH调节域一样折叠。苏氨酸脱氨酶的调节域虽然不是ACT序列家族的成员，但在结构上与成对的3PGDH调节域相似。ACT类结构域的重复可以创建具有复杂调控模式的不等价的配体结合位点。对这种系统的结构和机制的研究才刚刚开始。
A novel ligand-binding domain, named the 'ACT domain, was recently identified by a PSI-BLAST search. The archetypical ACT domain is the C-terminal regulatory domain of 3-phosphoglycerate dehydrogenase (3PGDH), which folds with a ferredoxin-like beta alpha beta beta alpha beta topology. A pair of ACT domains form an eight-stranded antiparallel sheet with two molecules of the allosteric inhibitor serine bound in the interface. The ACT domain is found in a variety of contexts and is proposed to be a conserved regulatory ligand binding fold. Rat phenylalanine hydroxylase has a regulatory domain with a similar fold, but different ligand-binding mode. Putative ACT domains in some proteins of unknown structure (e.g. acetohydroxyacid synthase regulatory subunits) may also fold like the 3PGDH regulatory domain. The regulatory domain of threonine deaminase, although not a member of the ACT sequence family, is similar in structure to the paired 3PGDH regulatory domains. Repeats of ACT-like domains can create nonequivalent ligand-binding sites with the potential for complex regulatory patterns. The structures and mechanisms of such systems have only begun to be examined.