Background: Aquaporins, also known as major intrinsic proteins (MIPs), facilitate the membrane diffusion of water and some other small solutes. The roles of MIPs in plant physiological processes are established and now their roles in plant-pathogen interactions are getting more attention.

Objective: To investigate the evolution, diversity, and structural insights of Phytophthora MIPs (PhyMIPs) and to compare them to those in other domains of life.

Methods: Bioinformatics approaches were used to identify and characterize the PhyMIPs. The phylogenetic analysis was done with MEGA7.0 using maximum likelihood method. The prediction of transmembrane α-helices was done by using SOSUI and TMpred servers, and that of subcellular localization was performed with WoLF PSORT and Cello prediction system. The structure of PhyMIP genes was predicted by GeneMark.hmm ES-3.0 program. The 3D homology models were generated using the Molecular Operating Environment software and the stereochemical quality of the templates and models was assessed by PROCHECK. The PoreWalker server was used to detect and characterize PhyMIP channels from their 3D structural models.

Results: Herein, we identified 17, 24, 27, 19, 19, and 22 full-length MIPs, respectively, in the genomes of six Phytophthora species, P. infestans, P. parasitica, P. sojae, P. ramorum, P. capsici, and P. cinnamomi. Phylogenetic analysis showed that the PhyMIPs formed a completely distinct clade from their counterparts in other taxa and were clustered into nine subgroups. Sequence and structural properties indicated that the primary selectivity-related constrictions, including aromatic arginine (ar/R) selectivity filter and Froger's positions in PhyMIPs were distinct from those in other taxa. The substitutions in the conserved Asn-Pro-Ala motifs in loops B and E of many PhyMIPs were also divergent from those in other taxonomic domains. The group-specific consensus sequences/ motifs deciphered in different loops and transmembrane α-helices of PhyMIPs were distinct from those in plants, animals, and other microbes.

Conclusion: This study represents PhyMIPs with distinct evolutionary and structural properties, and the data collectively indicates that PhyMIPs might have novel functions.

背景：水通道蛋白，也称为主要内在蛋白 (MIP)，可促进水和其他一些小溶质的膜扩散。MIPs 在植物生理过程中的作用已经确立，现在它们在植物-病原体相互作用中的作用越来越受到关注。

目的：研究疫霉属 MIPs (PhyMIPs) 的进化、多样性和结构见解，并将它们与其他生命领域的进行比较。

方法：使用生物信息学方法来识别和表征 PhyMIP。MEGA7.0 系统发育分析采用最大似然法。跨膜α-螺旋的预测使用SOSUI和TMpred服务器进行，​​亚细胞定位使用WoLF PSORT和Cello预测系统进行。PhyMIP基因的结构通过GeneMark.hmm ES-3.0程序进行预测。使用分子操作环境软件生成 3D 同源模型，并通过 PROCHECK 评估模板和模型的立体化学质量。PoreWalker 服务器用于从其 3D 结构模型中检测和表征 PhyMIP 通道。

结果：在本文中，我们在 6 个疫霉属物种（P. infestans、P. parasitica、P. sojae、P. ramorum、P. . 辣椒和肉桂。系统发育分析表明，PhyMIPs 与其他分类群中的对应物形成了一个完全不同的进化枝，并被分为九个亚组。序列和结构特性表明主要选择性相关收缩，包括芳香精氨酸 (ar/R) 选择性过滤器和 Froger 在 PhyMIP 中的位置与其他分类群中的不同。许多 PhyMIP 的环 B 和环 E 中保守的 Asn-Pro-Ala 基序中的替换也不同于其他分类域中的替换。

结论：这项研究代表了具有不同进化和结构特性的 PhyMIP，数据共同表明 PhyMIP 可能具有新的功能。