Mt Albert Research Centre, The New Zealand Institute for Plant and Food Research Limited, Auckland 1025, New Zealand.
School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand.
Int J Mol Sci. 2023 Sep 28;24(19):14664. doi: 10.3390/ijms241914664.
The YopJ group of acetylating effectors from phytopathogens of the genera and have been widely studied to understand how they modify and suppress their host defence targets. In contrast, studies on a related group of effectors, the Eop1 group, lag far behind. Members of the Eop1 group are widely present in the clade of Gram-negative bacteria, which contains phytopathogens, non-pathogens and potential biocontrol agents, implying that they may play an important role in agroecological or pathological adaptations. The lack of research in this group of YopJ effectors has left a significant knowledge gap in their functioning and role. For the first time, we perform a comparative analysis combining AlphaFold modelling, in planta transient expressions and targeted mutational analyses of the Eop1 group effectors from the clade, to help elucidate their likely activity and mechanism(s). This integrated study revealed several new findings, including putative binding sites for inositol hexakisphosphate and acetyl coenzyme A and newly postulated target-binding domains, and raises questions about whether these effectors function through a catalytic triad mechanism. The results imply that some Eop1s may use a catalytic dyad acetylation mechanism that we found could be promoted by the electronegative environment around the active site.
植物病原菌属和属的 YopJ 组乙酰化效应因子已被广泛研究，以了解它们如何修饰和抑制宿主防御靶标。相比之下，对相关效应因子 Eop1 组的研究则远远落后。Eop1 组的成员广泛存在于革兰氏阴性细菌的 分支中，其中包含植物病原菌、非病原菌和潜在的生物防治剂，这意味着它们可能在农业生态或病理适应中发挥重要作用。由于缺乏对这组 YopJ 效应因子的研究，导致人们对它们的功能和作用存在重大的知识空白。我们首次进行了比较分析，结合 AlphaFold 建模、植物体内瞬时表达和靶向突变分析，对 分支中的 Eop1 组效应因子进行了研究，以帮助阐明它们的可能活性和作用机制。这项综合研究揭示了一些新的发现，包括肌醇六磷酸和乙酰辅酶 A 的可能结合位点以及新提出的靶标结合结构域，并提出了这些效应因子是否通过催化三联体机制发挥作用的问题。研究结果表明，一些 Eop1 可能采用我们发现的催化二联体乙酰化机制，这种机制可能受到活性位点周围的负电性环境的促进。
