Amoebiasis is the third leading cause of death among protozoon parasitic diseases in the lower-middle income countries. Understanding the molecular events that control gene expression such as transcription factors, their DNA binding mode and target sequences can help to develop new antiamoebic drugs against Entamoeba histolytica. In this paper we performed a genome and structural analysis of a specific transcription factor. The genome of E. histolytica codifies for 9 EhMybSHAQKYF proteins, which are a family within a large group of 34 Myb-DNA-binding domain (Myb-DBD) containing proteins. Here we compared Entamoeba Myb-SHAQKYF proteins with Myb-like proteins from the Reveille (RVE) family, important regulators of plant circadian networks. This comparison could lead to stablish their role in E. histolytica life cycle. We show that the ehmybshaqkyf genes are differentially expressed in trophozoites under basal cell culture conditions. An in-silico analysis predicts that members of this group harbor a highly conserved and structured Myb-DBD and a large portion of intrinsically disordered residues. As the Myb-DBD of these proteins harbors a distinctive Q[VI]R[ST]HAQK[YF]F sequence in its putative third α-helix, we consider relevant to determine the three-dimensional (3D) structure of one of them. An NMR structure of the Myb-DBD of EhMybS3 shows that this protein is composed of three α-helices stabilized by a hydrophobic core, similar to Myb proteins of different kingdoms. It is remarkable that despite not sharing similarities in their amino acid sequences, the structure of the Myb-DBD of the EhMybS3 is well conserved in this early branching eukaryote.

阿米巴虫病是中低收入国家原生动物寄生虫病中的第三大死亡原因。了解分子事件控制基因表达如转录因子，它们的DNA结合模式和目标序列可以有助于开发新的药物antiamoebic对阿米巴。在本文中，我们进行了基因组和特定转录因子的结构分析。溶组织性大肠杆菌的基因组编码9种EhMybSHAQKYF蛋白，这些蛋白是包含34个Myb-DNA结合域（Myb-DBD）的蛋白质的一大群中的一个家族。在这里，我们将Entamoeba Myb-SHAQKYF蛋白与Reveille（RVE）家族的Myb样蛋白进行了比较，后者是植物昼夜节律网络的重要调节剂。这种比较可能会稳定他们在溶血性大肠杆菌的生命周期中的作用。我们显示，在基础细胞培养条件下，滋养体中ehmybshaqkyf基因差异表达。一项计算机分析表明，该组成员具有高度保守和结构化的Myb-DBD以及大部分内在无序的残基。由于这些蛋白质的Myb-DBD具有独特的Q [ VI ] R [ ST] HAQK [ YF ] F序列在其推定的第三个α-螺旋中，我们认为与确定其中一个的三维（3D）结构有关。EhMybS3的Myb-DBD的NMR结构表明，该蛋白由三个由疏水核稳定的α-螺旋组成，类似于不同王国的Myb蛋白。值得注意的是，尽管在氨基酸序列上没有共享相似性，但EhMybS3的Myb-DBD的结构在这个早期分支的真核生物中却非常保守。