The haloacid dehalogenase (HAD) superfamily is one of the largest known groups of enzymes and the majority of its members catalyze the hydrolysis of phosphoric acid monoesters into a phosphate ion and an alcohol. Despite the fact that sequence similarity between HAD phosphatases is generally very low, the members of the family possess some characteristic features, such as a Rossmann‐like fold, HAD signature motifs or the requirement for Mg²⁺ ion as an obligatory cofactor. This study focuses on a new hypothetical HAD phosphatase from Thermococcus thioreducens. The protein crystallized in space group P2₁2₁2, with unit‐cell parameters a = 66.3, b = 117.0, c = 33.8 Å, and the crystals contained one molecule in the asymmetric unit. The protein structure was determined by X‐ray crystallography and was refined to 1.75 Å resolution. The structure revealed a putative active site common to all HAD members. Computational docking into the crystal structure was used to propose substrates of the enzyme. The activity of this thermophilic enzyme towards several of the selected substrates was confirmed at temperatures of 37°C as well as 60°C.

中文翻译：

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一种新型的结构特征的卤代酸脱卤酶超家族磷酸酶，来自硫代热球菌，具有多种底物特异性。

卤代酸脱卤酶（HAD）超家族是已知的最大酶类之一，其大多数成员催化磷酸单酯水解为磷酸根离子和醇。尽管事实上HAD磷酸酶之间的序列相似性很低，但该家族的成员仍具有某些特征，例如罗斯曼样折叠，HAD签名基序或需要Mg ²⁺离子作为强制性辅因子。这项研究集中在一种新的假设的硫嗜热球菌的HAD磷酸酶。蛋白质在空间群P 2 ₁ 2 ₁ 2中结晶，单位细胞参数a = 66.3，b = 117.0，c＝ 33.8埃，并且晶体在不对称单元中包含一个分子。通过X射线晶体学测定蛋白质结构，并将其精制至1.75Å分辨率。该结构揭示了所有HAD成员共有的推定活性位点。计算对接至晶体结构用于提出酶的底物。在37℃和60℃的温度下证实了该嗜热酶对几种选定底物的活性。