Structure of L-aspartate oxidase: implications for the succinate dehydrogenase/fumarate reductase oxidoreductase family
Structure of L-aspartate oxidase: implications for the succinate dehydrogenase/fumarate reductase oxidoreductase family
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DOI：
10.1016/s0969-2126(99)80099-9
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发表时间：
1999-07-15
期刊：
影响因子：
5.7
通讯作者：
Ronchi, S
中科院分区：
文献类型：
--
作者：
Mattevi, A;Tedeschi, G;Ronchi, S
背景：鉴于NAD(+)在细胞代谢中的重要作用，参与细菌NAD(+)生物合成的酶可能是抗病原菌药物设计的靶点。该途径的第一反应是由L-天冬氨酸氧化酶(LASPO)催化的，LASPO是一种黄素酶，以分子氧或富马酸为电子受体，将天冬氨酸转化为亚氨基天冬氨酸。LASPO与琥珀酸脱氢酶(SDH)和富马酸还原酶(FRD)的黄素蛋白亚基有相当大的序列同源性。结果：从大肠杆菌中获得的LASPO的晶体结构达到2.2埃分辨率，该酶显示了一个新的FAD依赖的蛋白质折叠包括三个结构域：带有二核苷酸结合折叠的FAD结合结构域、C端三螺旋束结构域、以及在拓扑上类似于菠菜核酮糖-1，5-二磷酸羧化酶/加氧酶小亚基的α+β封闭域。结论：LASPO、SDH和FRD在三个结构域中都存在一些严格保守的残基，表明LASPO、SDH和FRD具有相同的整体折叠拓扑结构。这些保守残基中的许多都位于PAD结合部位和活性中心，暗示了类似的催化机制。因此，LASPO、SDH和FRD形成了一类功能和结构相关的氧化还原酶，它们都能够还原富马酸和氧化二元酸底物。
Background: Given the vital role of NAD(+) in cell metabolism, the enzymes involved in bacterial de novo NAD(+) biosynthesis are possible targets for drug design against pathogenic bacteria, The first reaction in the pathway is catalysed by L-aspartate oxidase (LASPO), a flavoenzyme that converts aspartate to iminoaspartate using either molecular oxygen or fumarate as electron accepters, LASPO has considerable sequence homology with the flavoprotein subunits of succinate dehydrogenase (SDH) and fumarate reductase (FRD).Results: The crystal structure of the apoform of LASPO from Escherichia coli has been determined to 2.2 Angstrom resolution, The enzyme shows a novel fold for an FAD-dependent protein, comprising a three-domain structure: an FAD-binding domain with the dinucleotide-binding fold, a C-terminal three-helical bundle domain, and an alpha+beta capping domain, which is topologically similar to the small subunit of spinach ribulose-1,5-bisphosphate carboxylase/oxygenase. The interface between the PAD-binding and capping domains defines a cleft in which the active site is located.Conclusions: A number of strictly conserved residues present in all three domains indicate that LASPO, SDH and FRD share the same overall folding topology. Many of these conserved residues are in the PAD-binding site and active centre, suggesting a similar catalytic mechanism. Thus, LASPO, SDH and FRD form a class of functionally and structurally related oxidoreductases that are all able to reduce fumarate and to oxidise a dicarboxylate substrate.