Structure-function correlation in glycine oxidase from Bacillus subtilis
Structure-function correlation in glycine oxidase from Bacillus subtilis
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DOI：
10.1074/jbc.m401224200
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发表时间：
2004-07-09
影响因子：
4.8
通讯作者：
Pollegioni, L
中科院分区：
文献类型：
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作者：
Mörtl, M;Diederichs, K;Pollegioni, L
黄素蛋白甘氨酸氧化酶 (GO) 的结构-功能关系最近被提出作为枯草芽孢杆菌硫胺素生物合成的第一种酶，已通过结构和功能研究相结合进行了研究。 GO-乙醇酸复合物的结构在 1.8 埃下测定，在该分辨率下可以描绘出参与 FAD 结合和底物相互作用的残基的草图。 GO可以被认为是黄素蛋白“胺氧化酶”类的成员，例如D-氨基酸氧化酶和单体肌氨酸氧化酶。利用所获得的GO模型，可以详细分析单体-单体相互作用，从而解释GO稳定四聚寡聚状态的结构基础，这是黄素氧化酶GR(2)亚家族所独有的。另一方面，GO的三维结构和功能实验并没有提供这种低聚状态的功能意义； GO 不表现出变构行为。结果并未阐明该酶在枯草芽孢杆菌中的代谢作用； GO 的广泛底物特异性无法与硫胺素生物合成中推断的功能相关，并且该结构没有显示 GO 如何与硫胺素生物合成中的后续酶 ThiS 相互作用。然而，他们确实排除了该酶对伯胺或仲胺的一般分解代谢作用，因为甘氨酸、肌氨酸或 D-丙氨酸作为碳源或氮源不能诱导 GO 的表达。
Structure-function relationships of the flavoprotein glycine oxidase ( GO), which was recently proposed as the first enzyme in the biosynthesis of thiamine in Bacillus subtilis, has been investigated by a combination of structural and functional studies. The structure of the GO-glycolate complex was determined at 1.8 Angstrom, a resolution at which a sketch of the residues involved in FAD binding and in substrate interaction can be depicted. GO can be considered a member of the "amine oxidase" class of flavoproteins, such as D-amino acid oxidase and monomeric sarcosine oxidase. With the obtained model of GO the monomer-monomer interactions can be analyzed in detail, thus explaining the structural basis of the stable tetrameric oligomerization state of GO, which is unique for the GR(2) subfamily of flavooxidases. On the other hand, the three-dimensional structure of GO and the functional experiments do not provide the functional significance of such an oligomerization state; GO does not show an allosteric behavior. The results do not clarify the metabolic role of this enzyme in B. subtilis; the broad substrate specificity of GO cannot be correlated with the inferred function in thiamine biosynthesis, and the structure does not show how GO could interact with ThiS, the following enzyme in thiamine biosynthesis. However, they do let a general catabolic role of this enzyme on primary or secondary amines to be excluded because the expression of GO is not inducible by glycine, sarcosine, or D-alanine as carbon or nitrogen sources.