Laboratorio de Fisiología de Estrés Abiótico en Plantas, Unidad de Biotecnología, INTECH - CONICET - UNSAM, Intendente Marino KM 8.2 - B7130IWA Chascomús, Buenos Aires, Argentina.
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Apartado Postal 70-367, Coyoacán, 04510, México City, Mexico.
BMC Evol Biol. 2019 Jan 21;19(1):28. doi: 10.1186/s12862-019-1361-z.
The polyamine oxidases (PAOs) catabolize the oxidative deamination of the polyamines (PAs) spermine (Spm) and spermidine (Spd). Most of the phylogenetic studies performed to analyze the plant PAO family took into account only a limited number and/or taxonomic representation of plant PAOs sequences.
Here, we constructed a plant PAO protein sequence database and identified four subfamilies. Subfamily PAO back conversion 1 (PAObc1) was present on every lineage included in these analyses, suggesting that BC-type PAOs might play an important role in plants, despite its precise function is unknown. Subfamily PAObc2 was exclusively present in vascular plants, suggesting that t-Spm oxidase activity might play an important role in the development of the vascular system. The only terminal catabolism (TC) PAO subfamily (subfamily PAOtc) was lost in Superasterids but it was present in all other land plants. This indicated that the TC-type reactions are fundamental for land plants and that their function could being taken over by other enzymes in Superasterids. Subfamily PAObc3 was the result of a gene duplication event preceding Angiosperm diversification, followed by a gene extinction in Monocots. Differential conserved protein motifs were found for each subfamily of plant PAOs. The automatic assignment using these motifs was found to be comparable to the assignment by rough clustering performed on this work.
The results presented in this work revealed that plant PAO family is bigger than previously conceived. Also, they delineate important background information for future specific structure-function and evolutionary investigations and lay a foundation for the deeper characterization of each plant PAO subfamily.
多胺氧化酶（PAOs）催化多胺（PAs）精脒（Spm）和精胺（Spd）的氧化脱氨作用。大多数用于分析植物 PAO 家族的系统发育研究仅考虑了有限数量和/或植物 PAO 序列的分类学代表性。
在这里，我们构建了一个植物 PAO 蛋白质序列数据库，并鉴定了四个亚科。PAObc1 亚科存在于这些分析中包含的每个谱系中，这表明 BC 型 PAOs 可能在植物中发挥重要作用，尽管其确切功能尚不清楚。PAObc2 亚科仅存在于维管植物中，这表明 t-Spm 氧化酶活性可能在维管系统的发育中发挥重要作用。唯一的末端分解代谢（TC）PAO 亚科（PAOtc 亚科）在超级类群中丢失，但在所有其他陆地植物中都存在。这表明 TC 型反应对于陆地植物是基本的，它们的功能可能在超级类群中被其他酶取代。PAObc3 亚科是在被子植物多样化之前发生的基因复制事件的结果，随后在单子叶植物中发生了基因灭绝。在每个植物 PAO 亚科中都发现了不同的保守蛋白基序。使用这些基序的自动分配被发现与在这项工作中执行的粗略聚类分配相当。
本工作中提出的结果表明，植物 PAO 家族比以前想象的要大。此外，它们为未来的特定结构-功能和进化研究勾勒出重要的背景信息，并为每个植物 PAO 亚科的更深入特征描述奠定了基础。
