Computation-Facilitated Assignment of the Function in the Enolase Superfamily: A Regiochemically Distinct Galactarate Dehydratase from <i>Oceanobacillus iheyensis</i>,
作者:John F. Rakus、Chakrapani Kalyanaraman、Alexander A. Fedorov、Elena V. Fedorov、Fiona P. Mills-Groninger、Rafael Toro、Jeffrey Bonanno、Kevin Bain、J. Michael Sauder、Stephen K. Burley、Steven C. Almo、Matthew P. Jacobson、John A. Gerlt
DOI:10.1021/bi901731c
日期:2009.12.8
l-talarate/galactarate dehydratase (TalrD/GalrD). On the basis of the different active site structures and different regiochemistries, we recognize that these functions represent an example of apparent, not actual, convergent evolution of function. The structure of GalrD-II and its active site architecture allow identification of the seventh functionally and structurally characterized subgroup in the enolase superfamily
来自Oceanobacillus iheyensis (GI 23100298,IMG 基因座标签 Ob2843,PDB 条目 2OQY)的烯醇化酶超家族的未表征成员的结构由纽约 SGX 结构基因组学研究中心 (NYSGXRC) 确定。该结构包含两个 Mg 2+离子,彼此相距 10.4 Å,其中一个位于 (β/α) 7中的规范位置β-桶结构域(尽管第五条 β-链末端的配体是 His,在超家族的结构特征成员中是前所未有的);第二个位于加帽域内的一个新站点。将单糖和二糖库与活性位点进行计算机对接,预测二糖可能是底物。酸糖物理库的活性筛选将半乳糖二酸鉴定为底物 ( k cat = 6.8 s −1 , K M = 620 μM, k cat / K M = 1.1 × 10 4 M −1 s −1), 允许将 Ob2843 功能分配为半乳糖二酸脱水酶 (GalrD-II)。催化受损的 Y90F 突变体与