RLP-AgroScience GmbH, AlPlanta-Institute for Plant Research, Breitenweg 71, 67435 Neustadt, Germany.
Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schrödinger Str. 56, 67663 Kaiserslautern, Germany.
Int J Mol Sci. 2023 Jan 4;24(2):968. doi: 10.3390/ijms24020968.
' Phytoplasma mali' ('. P. mali') has only one major membrane protein, the immunodominant membrane protein (Imp), which is regarded as being close to the ancestor of all phytoplasma immunodominant membrane proteins. Imp binds to actin and possibly facilitates its movement in the plant or insect host cells. However, protein sequences of Imp are quite diverse among phytoplasma species, thus resulting in difficulties in identifying conserved domains across species. In this work, we compare Imp protein sequences of '. P. mali' strain PM19 (Imp-PM19) with Imp of different strains of '. P. mali' and identify its actin-binding domain. Moreover, we show that Imp binds to the actin of apple (), which is the host plant of '. P. mali'. Using molecular and scanning force spectroscopy analysis, we find that the actin-binding domain of Imp-PM19 contains a highly positively charged amino acid cluster. Our result could allow investigating a possible correlation between Imp variants and the infectivity of the corresponding '. P. mali' isolates.
' 苹果韧皮部杆菌 '（'. P. mali'）仅有一个主要的膜蛋白，即免疫显性膜蛋白（Imp），它被认为是所有植原体免疫显性膜蛋白的祖先。Imp 与肌动蛋白结合，并可能促进其在植物或昆虫宿主细胞中的运动。然而，Imp 的蛋白序列在植原体种间差异很大，因此导致在种间识别保守结构域存在困难。在这项工作中，我们比较了 PM19 菌株（Imp-PM19）的 Imp 蛋白序列与不同 '. P. mali' 菌株的 Imp，并鉴定了其肌动蛋白结合域。此外，我们表明 Imp 与苹果（Malus domestica）的肌动蛋白结合，苹果是 '. P. mali' 的宿主植物。通过分子和扫描力谱分析，我们发现 Imp-PM19 的肌动蛋白结合域包含一个高度带正电荷的氨基酸簇。我们的结果可以研究 Imp 变体与相应 '. P. mali' 分离株的感染力之间可能存在的相关性。
