The end-binding proteins are a family of microtubule-associated proteins; this family belongs to plus-end-tracking proteins (+TIPs) that regulate microtubule growth and stabilisation. Although the genes encoding EB proteins are found in all eukaryotic genomes, most studies of them have centred on one or another taxonomic group, without a broad comparative analysis. Here, we present a first phylogenetic analysis and a comparative analysis of domain structures of diatom EB proteins in comparison with other phyla of Chromista, red and green algae, as well as model organisms A. thaliana and H. sapiens. Phylogenetically, diatom EB proteins are separated into six clades, generally corresponding to the phylogeny of their respective organisms. The domain structure of this family is highly variable, but the CH and EBH domains responsible for binding tubulin and other MAPs are mostly conserved. Homologous modelling of the F. cylindrus EB protein shows that conserved motifs of the CH domain are positioned on the protein surface, which is necessary for their functioning. We hypothesise that high variance of the diatom C-terminal domain is caused by previously unknown interactions with a CAP-GLY motif of dynactin subunit p150. Our findings contribute to wider possibilities for further investigations of the cytoskeleton in diatoms.

末端结合蛋白是一个微管相关蛋白家族。该家族属于调节微管生长和稳定的加端跟踪蛋白 (+TIP)。尽管在所有真核生物基因组中都发现了编码 EB 蛋白的基因，但对它们的大多数研究都集中在一个或另一个分类群上，没有进行广泛的比较分析。在这里，我们对硅藻 EB 蛋白的结构域结构进行了首次系统发育分析和比较分析，并与 Chromista 的其他门、红藻和绿藻以及模式生物拟南芥和智人进行了比较。. 在系统发育上，硅藻 EB 蛋白分为六个进化枝，通常对应于它们各自生物体的系统发育。该家族的结构域结构高度可变，但负责结合微管蛋白和其他 MAP 的 CH 和 EBH 结构域大多是保守的。F. cylindrus EB 蛋白的同源模型表明，CH 结构域的保守基序位于蛋白质表面，这是其功能所必需的。我们假设硅藻 C 末端结构域的高方差是由先前未知的与 dynactin 亚基 p150 的 CAP-GLY 基序的相互作用引起的。我们的研究结果为进一步研究硅藻中的细胞骨架提供了更广泛的可能性。