Structure of Pseudomonas aeruginosa spermidine dehydrogenase: a polyamine oxidase with a novel heme-binding fold
Structure of Pseudomonas aeruginosa spermidine dehydrogenase: a polyamine oxidase with a novel heme-binding fold
复制标题
铜绿假单胞菌亚精胺脱氢酶的结构：一种具有新型血红素结合折叠的多胺氧化酶。
DOI：
10.1111/febs.16264
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发表时间：
2021-11-16
期刊：
影响因子：
5.4
通讯作者：
Bartlam, Mark
中科院分区：
文献类型：
--
作者：
Che, Shiyou;Liang, Yakun;Bartlam, Mark
条件致病菌铜绿假单胞菌可以利用多胺（包括腐胺、尸胺、4-氨基丁酸、亚精胺和精胺）作为其唯一的碳源和氮源。亚精胺脱氢酶（SpdH）是铜绿假单胞菌两条多胺利用途径之一，但其结构和功能尚不清楚。在这里，我们报告的第一个晶体结构的SpdH从铜绿假单胞菌到1.85埃分辨率。由此产生的核心结构证实，SpdH属于多胺氧化酶（PAO）的家庭与黄素结合和底物结合域。一个独特的N-末端延伸包裹在黄素结合结构域的SpdH和所需的血红素结合，放置在靠近FAD辅因子的血红素辅因子。结构和突变分析表明，在FAD异咯嗪环的背面推定的活性位点的残基形成的催化机器的一部分。PaSpdH具有不寻常的活性位点，并且缺乏保守的赖氨酸，该赖氨酸形成迄今为止表征的其他PAO酶中的赖氨酸-水-黄素N5原子相互作用的一部分。突变分析进一步证实血红素是催化活性所必需的。这项工作提供了一个重要的起点，了解的作用，普遍存在于铜绿假单胞菌菌株，在多胺代谢。
The opportunistic pathogen Pseudomonas aeruginosa can utilize polyamines (including putrescine, cadaverine, 4-aminobutyrate, spermidine, and spermine) as its sole source of carbon and nitrogen. Spermidine dehydrogenase (SpdH) is a component of one of the two polyamine utilization pathways identified in P. aeruginosa, but little is known about its structure and function. Here, we report the first crystal structure of SpdH from P. aeruginosa to 1.85 angstrom resolution. The resulting core structure confirms that SpdH belongs to the polyamine oxidase (PAO) family with flavin-binding and substrate-binding domains. A unique N-terminal extension wraps around the flavin-binding domain of SpdH and is required for heme binding, placing a heme cofactor in close proximity to the FAD cofactor. Structural and mutational analysis reveals that residues in the putative active site at the re side of the FAD isoalloxazine ring form part of the catalytic machinery. PaSpdH features an unusual active site and lacks the conserved lysine that forms part of a lysine-water-flavin N5 atom interaction in other PAO enzymes characterized to date. Mutational analysis further confirms that heme is required for catalytic activity. This work provides an important starting point for understanding the role of SpdH, which occurs universally in P. aeruginosa strains, in polyamine metabolism.