Begley Darren W, Davies Douglas R, Hartley Robert C, Hewitt Stephen N, Rychel Amanda L, Myler Peter J, Van Voorhis Wesley C, Staker Bart L, Stewart Lance J
Seattle Structural Genomics Center for Infectious Disease (http://www.ssgcid.org), USA.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2011 Sep 1;67(Pt 9):1060-9. doi: 10.1107/S1744309111014436. Epub 2011 Aug 13.
Glutaric acidemia type 1 is an inherited metabolic disorder which can cause macrocephaly, muscular rigidity, spastic paralysis and other progressive movement disorders in humans. The defects in glutaryl-CoA dehydrogenase (GCDH) associated with this disease are thought to increase holoenzyme instability and reduce cofactor binding. Here, the first structural analysis of a GCDH enzyme in the absence of the cofactor flavin adenine dinucleotide (FAD) is reported. The apo structure of GCDH from Burkholderia pseudomallei reveals a loss of secondary structure and increased disorder in the FAD-binding pocket relative to the ternary complex of the highly homologous human GCDH. After conducting a fragment-based screen, four small molecules were identified which bind to GCDH from B. pseudomallei. Complex structures were determined for these fragments, which cause backbone and side-chain perturbations to key active-site residues. Structural insights from this investigation highlight differences from apo GCDH and the utility of small-molecular fragments as chemical probes for capturing alternative conformational states of preformed protein crystals.
戊二酸血症1型是一种遗传性代谢紊乱疾病，可导致人类出现巨头畸形、肌肉僵硬、痉挛性瘫痪及其他进行性运动障碍。与该疾病相关的戊二酰辅酶A脱氢酶（GCDH）缺陷被认为会增加全酶不稳定性并减少辅因子结合。在此，报道了在不存在辅因子黄素腺嘌呤二核苷酸（FAD）的情况下对GCDH酶的首次结构分析。来自类鼻疽伯克霍尔德菌的GCDH无辅基结构显示，相对于高度同源的人类GCDH三元复合物，其二级结构丧失且FAD结合口袋中的无序性增加。在进行基于片段的筛选后，鉴定出了四种与类鼻疽伯克霍尔德菌的GCDH结合的小分子。确定了这些片段的复合物结构，它们会导致关键活性位点残基的主链和侧链发生扰动。该研究的结构见解突出了与无辅基GCDH的差异，以及小分子片段作为化学探针用于捕获预制蛋白质晶体替代构象状态的效用。
