Structure and Function of CutC Choline Lyase from Human Microbiota Bacterium Klebsiella pneumoniae
Structure and Function of CutC Choline Lyase from Human Microbiota Bacterium Klebsiella pneumoniae
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DOI：
10.1074/jbc.m115.670471
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发表时间：
2015-08-28
影响因子：
4.8
通讯作者：
Tars, Kaspars
中科院分区：
文献类型：
--
作者：
Kalnins, Gints;Kuka, Janis;Tars, Kaspars
背景：细菌甘氨酰自由基酶CutC将胆碱转化为三甲胺，这是一种参与多种疾病发病机制的代谢物。结果：与底物结合的CutC与无底物的CutC结构有显著差异。结论：胆碱结合到活性位点引发构象从开放到封闭的变化。重要性：CutC胆碱三甲基胺裂解酶是一种厌氧细菌甘氨酰自由基酶（GRE），能裂解胆碱生成三甲基胺（TMA）和乙醛。在人类中，TMA完全由肠道微生物群产生，其代谢产物氧化三甲胺与心血管疾病的高风险有关。因此，关于TMA产生酶的三维结构的信息对于微生物靶向药物发现是重要的。我们已经克隆，表达，并纯化的CutC GRE和激活酶CutD从克雷伯氏肺炎，人类微生物群的代表。我们已经确定了第一晶体结构的胆碱结合和胆碱自由形式的CutC，并已发现，胆碱在配体结合位点的结合触发酶结构的构象变化，尚未观察到的任何其他特征的GRE的功能。
Background: The bacterial glycyl radical enzyme CutC converts choline to trimethylamine, a metabolite involved in pathogenesis of several diseases. Results: The structures of substrate-bound and substrate-free CutC revealed significant differences. Conclusion: Choline binding to the active site triggers a conformational change from the open to closed form. Significance: A novel substrate-driven conformational mechanism and a potential target for drug design have been identified.CutC choline trimethylamine-lyase is an anaerobic bacterial glycyl radical enzyme (GRE) that cleaves choline to produce trimethylamine (TMA) and acetaldehyde. In humans, TMA is produced exclusively by the intestinal microbiota, and its metabolite, trimethylamine oxide, has been associated with a higher risk of cardiovascular diseases. Therefore, information about the three-dimensional structures of TMA-producing enzymes is important for microbiota-targeted drug discovery. We have cloned, expressed, and purified the CutC GRE and the activating enzyme CutD from Klebsiella pneumoniae, a representative of the human microbiota. We have determined the first crystal structures of both the choline-bound and choline-free forms of CutC and have discovered that binding of choline at the ligand-binding site triggers conformational changes in the enzyme structure, a feature that has not been observed for any other characterized GRE.