Urkinase: Structure of acetate kinase, a member of the ASKHA superfamily of phosphotransferases
Urkinase: Structure of acetate kinase, a member of the ASKHA superfamily of phosphotransferases
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DOI：
10.1128/jb.183.2.680-686.2001
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发表时间：
2001-01-01
影响因子：
3.2
通讯作者：
Hasson, MS
中科院分区：
文献类型：
--
作者：
Buss, KA;Cooper, DR;Hasson, MS
乙酸激酶是一种广泛存在于细菌和酵母中的酶，催化乙酸的磷酸化。我们已经确定了三维结构的嗜热甲烷八叠球菌醋酸激酶结合ADP通过晶体学。正如我们先前预测的那样，乙酸激酶包含一个核心折叠，该核心折叠与甘油激酶、己糖激酶、70-kDa热裂解同源物（Hsc 70）和肌动蛋白的ADP结合结构域拓扑相同。许多带电荷的活性位点残基在乙酸激酶中是保守的，但在磷酸转移酶超家族中很少是保守的。多肽片段插入到超家族成员的核心折叠中的插入点的身份表明，这些插入存在于磷酸转移酶的共同祖先中。另一个显著的共同特征是直接在保守的甘氨酸残基（乙酸激酶中的Gly-331）之前的残基的不寻常的构象，所述甘氨酸残基结合ADP的醇-磷酸。结构、生物化学和地球化学考虑表明乙酸激酶可能是磷酸转移酶的ASKHA（乙酸和糖激酶/Hsc 70/肌动蛋白）超家族的祖先酶。
Acetate kinase, an enzyme widely distributed in the Bacteria and Archaea domains, catalyzes the phosphorylation of acetate. We have determined the three-dimensional structure of Methanosarcina thermophila acetate kinase bound to ADP through crystallography. As we previously predicted, acetate kinase contains a core fold that is topologically identical to that of the ADP-binding domains of glycerol kinase, hexokinase, the 70-kDa heat shack cognate (Hsc70), and actin. Numerous charged active-site residues are conserved within acetate kinases, but few are conserved within the phosphotransferase superfamily, The identity of the points of insertion of polypeptide segments into the core fold of the superfamily members indicates that the insertions existed in the common ancestor of the phosphotransferases. Another remarkable shared feature is the unusual, epsilon conformation of the residue that directly precedes a conserved glycine residue (Gly-331 in acetate kinase) that binds the ol-phosphate of ADP, Structural, biochemical, and geochemical considerations indicate that an acetate kinase may be the ancestral enzyme of the ASKHA (acetate and sugar kinases/Hsc70/actin) superfamily of phosphotransferases.