From the Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU.
the Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, and the Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
J Biol Chem. 2014 Nov 7;289(45):30889-99. doi: 10.1074/jbc.M114.604892. Epub 2014 Sep 12.
The PhoD family of extra-cytoplasmic phosphodiesterases are among the most commonly occurring bacterial phosphatases. The exemplars for this family are the PhoD protein of Bacillus subtilis and the phospholipase D of Streptomyces chromofuscus. We present the crystal structure of B. subtilis PhoD. PhoD is most closely related to purple acid phosphatases (PAPs) with both types of enzyme containing a tyrosinate-ligated Fe(3+) ion. However, the PhoD active site diverges from that found in PAPs and uses two Ca(2+) ions instead of the single extra Fe(2+), Mn(2+), or Zn(2+) ion present in PAPs. The PhoD crystals contain a phosphate molecule that coordinates all three active site metal ions and that is proposed to represent a product complex. A C-terminal helix lies over the active site and controls access to the catalytic center. The structure of PhoD defines a new phosphatase active site architecture based on Fe(3+) and Ca(2+) ions.
PhoD 家族的细胞外磷酸二酯酶是最常见的细菌磷酸酶之一。该家族的典型代表是枯草芽孢杆菌的 PhoD 蛋白和变色链霉菌的磷脂酶 D。我们展示了枯草芽孢杆菌 PhoD 的晶体结构。PhoD 与紫色酸性磷酸酶（PAPs）最为密切相关，这两种酶都含有一个酪氨酸配位的 Fe(3+)离子。然而，PhoD 的活性位点与 PAPs 中的活性位点不同，它使用两个 Ca(2+)离子代替 PAPs 中的单个额外的 Fe(2+)、Mn(2+)或 Zn(2+)离子。PhoD 晶体中含有一个磷酸分子，该分子与所有三个活性位点的金属离子配位，并被提议代表一个产物复合物。一个 C 端螺旋位于活性位点上方，控制着进入催化中心的通道。PhoD 的结构定义了一种基于 Fe(3+)和 Ca(2+)离子的新磷酸酶活性位点结构。
