Pongpom Monsicha, Khamto Nopawit, Sukantamala Panwarit, Kalawil Thitisuda, Wangsanut Tanaporn
Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
J Fungi (Basel). 2024 Sep 30;10(10):687. doi: 10.3390/jof10100687.
is a thermally dimorphic fungus that can cause life-threatening systemic mycoses, particularly in immunocompromised individuals. Fungal homeobox transcription factors control various developmental processes, including the regulation of sexual reproduction, morphology, metabolism, and virulence. However, the function of homeobox proteins in has not been fully explored. Here, we searched the genome for the total homeobox transcription factors and predicted their biological relevance by performing gene expression analysis in different cell types, including conidia, mycelia, yeasts, and during phase transition. RfeB is selected for further computational analysis since (i) its transcripts were differentially expressed in different phases of , and (ii) this protein contains the highly conserved protein-protein interaction region (IR), which could be important for pathobiology and have therapeutic application. To assess the structure-function of the IR region, in silico alanine substitutions were performed at three-conserved IR residues (Asp276, Glu279, and Gln282) of RfeB, generating a triple RfeB mutated protein. Using 3D modeling and molecular dynamics simulations, we compared the protein complex formation of wild-type and mutated RfeB proteins with the putative partner candidate TmSwi5. Our results demonstrated that the mutated RfeB protein exhibited increased free binding energy, elevated protein compactness, and a reduced number of atomic contacts, suggesting disrupted protein stability and interaction. Notably, our model revealed that the IR residues primarily stabilized the RfeB binding sites located in the central region (CR). This computational approach for protein mutagenesis could provide a foundation for future experimental studies on the functional characterization of RfeB and other homeodomain-containing proteins in .
是一种温度双态真菌，可引起危及生命的系统性真菌病，尤其是在免疫功能低下的个体中。真菌同源盒转录因子控制各种发育过程，包括有性生殖、形态、代谢和毒力的调节。然而，同源盒蛋白在 中的功能尚未得到充分探索。在这里，我们在 基因组中搜索了所有同源盒转录因子，并通过在不同细胞类型（包括分生孢子、菌丝体、酵母以及在相变过程中）进行基因表达分析来预测它们的生物学相关性。选择RfeB进行进一步的计算分析，原因如下：（i）其转录本在 的不同阶段差异表达；（ii）该蛋白包含高度保守的蛋白质 - 蛋白质相互作用区域（IR），这可能对病理生物学很重要并具有治疗应用价值。为了评估IR区域的结构 - 功能，在RfeB的三个保守IR残基（Asp276、Glu279和Gln282）处进行了计算机模拟丙氨酸取代，产生了一种三重RfeB突变蛋白。使用三维建模和分子动力学模拟，我们比较了野生型和突变型RfeB蛋白与假定的伙伴候选物TmSwi5的蛋白质复合物形成。我们的结果表明，突变型RfeB蛋白表现出增加的自由结合能、提高的蛋白质紧凑性和减少的原子接触数量，表明蛋白质稳定性和相互作用受到破坏。值得注意的是，我们的模型表明IR残基主要稳定位于中央区域（CR）的RfeB结合位点。这种蛋白质诱变的计算方法可为未来关于RfeB和 中其他含同源结构域蛋白的功能表征的实验研究提供基础。
