Structural and biochemical studies of human 4-hydroxy-2-oxoglutarate aldolase: implications for hydroxyproline metabolism in primary hyperoxaluria.
Structural and biochemical studies of human 4-hydroxy-2-oxoglutarate aldolase: implications for hydroxyproline metabolism in primary hyperoxaluria.
复制标题
DOI：
10.1371/journal.pone.0026021
复制
发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Lowther WT
中科院分区：
文献类型：
--
作者：
Riedel TJ;Johnson LC;Knight J;Hantgan RR;Holmes RP;Lowther WT
4-羟基-2-氧戊二酸醛缩酶是羟基脯氨酸降解途径中独特的酶，可催化HOG裂解成丙酮酸和乙醛酸酯。这种酶的突变被认为与原发性高草酸尿3型（PH3）中草酸盐的过量产生有关，尽管没有实验数据支持这一假设。此外，人类HOGA的身份，寡聚态，酶活性和晶体结构尚未实验确定。本研究用牛肾线粒体酶的质谱法鉴定了人HOGA （hHOGA）。hHOGA进行反醛醇裂解反应，类似于三聚体2-酮-3-脱氧-6-磷酸葡萄糖酸醛缩酶。然而，序列比较表明，HOGA与四聚体细菌二氢二吡啶合酶有关，但反应方向相反。测定了与丙酮酸结合的hHOGA的1.97 Å分辨率晶体结构，实现了HOG-Schiff碱中间体的建模和活性位点残基的鉴定。位点导向突变体的动力学分析支持了Lys196作为亲核试剂的重要性，Tyr168和Ser77作为质子接力的组成部分，Asn78和Ser198作为促进底物结合的独特残基。生化和结构数据支持hHOGA利用I型醛缩酶反应机制，但采用新的残基相互作用结合底物。PH3突变图谱确定了活性位点或四聚体组装中可能导致活性丧失的潜在重排。总之，这些数据为评估hHOGA的突变形式以及如何从药理学上恢复其活性奠定了基础。
4-hydroxy-2-oxoglutarate (HOG) aldolase is a unique enzyme in the hydroxyproline degradation pathway catalyzing the cleavage of HOG to pyruvate and glyoxylate. Mutations in this enzyme are believed to be associated with the excessive production of oxalate in primary hyperoxaluria type 3 (PH3), although no experimental data is available to support this hypothesis. Moreover, the identity, oligomeric state, enzymatic activity, and crystal structure of human HOGA have not been experimentally determined. In this study human HOGA (hHOGA) was identified by mass spectrometry of the mitochondrial enzyme purified from bovine kidney. hHOGA performs a retro-aldol cleavage reaction reminiscent of the trimeric 2-keto-3-deoxy-6-phosphogluconate aldolases. Sequence comparisons, however, show that HOGA is related to the tetrameric, bacterial dihydrodipicolinate synthases, but the reaction direction is reversed. The 1.97 Å resolution crystal structure of hHOGA bound to pyruvate was determined and enabled the modeling of the HOG-Schiff base intermediate and the identification of active site residues. Kinetic analyses of site-directed mutants support the importance of Lys196 as the nucleophile, Tyr168 and Ser77 as components of a proton relay, and Asn78 and Ser198 as unique residues that facilitate substrate binding. The biochemical and structural data presented support that hHOGA utilizes a type I aldolase reaction mechanism, but employs novel residue interactions for substrate binding. A mapping of the PH3 mutations identifies potential rearrangements in either the active site or the tetrameric assembly that would likely cause a loss in activity. Altogether, these data establish a foundation to assess mutant forms of hHOGA and how their activity could be pharmacologically restored.
登录
查看更多内容
影响因子：
3.9
作者：
Dobson, Renwick C. J.;Perugini, Matthew A.;Gerrard, Juliet A.
通讯作者：
Gerrard, Juliet A.
DOI：
10.1107/s1744309108033654
发表时间：
2008-12-01
影响因子：
0.9
作者：
Devenish, Sean R. A.;Gerrard, Juliet A.;Dobson, Renwick C. J.
通讯作者：
Dobson, Renwick C. J.
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
DOI：
10.1107/s0907444909042073
发表时间：
2010-01
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Chen VB;Arendall WB 3rd;Headd JJ;Keedy DA;Immormino RM;Kapral GJ;Murray LW;Richardson JS;Richardson DC
通讯作者：
Richardson DC
影响因子：
2.9
作者：
Blickling, S;Renner, C;Huber, R
通讯作者：
Huber, R