PHTHALATE DIOXYGENASE REDUCTASE - A MODULAR STRUCTURE FOR ELECTRON-TRANSFER FROM PYRIDINE-NUCLEOTIDES TO [2FE-2S]
PHTHALATE DIOXYGENASE REDUCTASE - A MODULAR STRUCTURE FOR ELECTRON-TRANSFER FROM PYRIDINE-NUCLEOTIDES TO [2FE-2S]
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DOI：
10.1126/science.1280857
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发表时间：
1992-12-04
期刊：
影响因子：
56.9
通讯作者：
LUDWIG, ML
中科院分区：
文献类型：
--
作者：
CORRELL, CC;BATIE, CJ;LUDWIG, ML
邻苯二甲酸酯双加氧酶还原酶（PDR）是一种典型的铁硫黄蛋白（36千道尔），它利用黄素单核苷酸（FMN）介导电子从双电子供体（还原性烟酰胺腺嘌呤核苷酸（NADH））转移到单电子受体[2Fe-2S]。用2.0埃分辨率分析了洋葱假单胞菌氧化后PDR的晶体结构；还原的PDR和吡啶核苷酸配合物在2.7埃分辨率下进行了分析。NADH， FMN和[2Fe-2S]簇，结合到不同的结构域，聚集在分子的中心裂缝附近，仅4.9埃将黄素8-甲基和连接到铁的半胱氨酸硫分开。结合FMN和[2Fe-2S]的结构域被包裹，使得黄素环和[2Fe-2S]核心的平面近似垂直。[2Fe-2S]基团与四个半胱氨酸结合在一个类似于植物铁氧化还蛋白的位置，但其氧化还原电位（pH 7.0时-174毫伏）远高于植物铁氧化还蛋白的电位。结构和序列的相似性使PDR属于一个独特的黄蛋白还原酶家族，它们都与铁氧还蛋白NADP+还原酶有关。
Phthalate dioxygenase reductase (PDR) is a prototypical iron-sulfur flavoprotein (36 kilodaltons) that utilizes flavin mononucleotide (FMN) to mediate electron transfer from the two-electron donor, reduced nicotinamide adenine nucleotide (NADH), to the one-electron acceptor, [2Fe-2S]. The crystal structure of oxidized PDR from Pseudomonas cepacia has been analyzed at 2.0 angstrom resolution resolution; reduced PDR and pyridine nucleotide complexes have been analyzed at 2.7 angstrom resolution. NADH, FMN, and the [2Fe-2S] cluster, bound to distinct domains, are brought together near a central cleft in the molecule, with only 4.9 angstroms separating the flavin 8-methyl and a cysteine sulfur ligated to iron. The domains that bind FMN and [2Fe-2S] are packed so that the flavin ring and the plane of the [2Fe-2S] core are approximately perpendicular. The [2Fe-2S] group is bound by four cysteines in a site resembling that in plant ferredoxins, but its redox potential (-174 millivolts at pH 7.0) is much higher than the potentials of plant ferredoxins. Structural and sequence similarities assign PDR to a distinct family of flavoprotein reductases, all related to ferredoxin NADP+-reductase.