In eukaryotes, chromosome ends (telomeres) are tethered to the inner nuclear membrane. During the early stages of meiosis, telomeres move along the nuclear membrane and gather near the spindle-pole body, resulting in a bouquet-like arrangement of chromosomes. This chromosomal configuration appears to be widely conserved among eukaryotes, and is assumed to play an important role in the normal progression of meiosis, by mediating the proper pairing of homologous chromosomes. In fission yeast, the Bqt1–Bqt2 protein complex plays a key role in tethering the telomere to the inner nuclear membrane. However, the structural details of the complex required to clarify how telomeres are gathered near the spindle-pole body remain enigmatic. Previously, we devised a preparation procedure for the Schizosaccharomyces japonicus Bqt1–Bqt2 complex, in which a SUMO tag was fused to the N-terminus of the Bqt1 protein. This allowed us to purify the Bqt1–Bqt2 complex from the soluble fraction. In the present study, we found that a maltose-binding protein homolog, Athe_0614, served as a better fusion partner than the SUMO protein, resulting in the marked increase in the solubility of the Bqt1–Bqt2 complex. The Athe_0614 fusion partner may open up new avenues for X-ray crystallographic analyses of the structure of the Bqt1–Bqt2 complex.

中文翻译：

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制备端粒束缚复合物Bqt1-Bqt2用于结构研究的改进方法。

在真核生物中，染色体末端（端粒）被束缚在核内膜上。在减数分裂的早期阶段，端粒沿着核膜移动并聚集在纺锤极体附近，导致染色体呈束状排列。这种染色体构型似乎在真核生物中被广泛保存，并被认为通过介导同源染色体的正确配对在减数分裂的正常进程中起重要作用。在裂变酵母中，Bqt1-Bqt2蛋白复合体在将端粒束缚到内核膜中起关键作用。然而，澄清端粒如何在纺锤极体附近聚集所需的复合物的结构细节仍然是个谜。以前，我们设计了日本裂殖酵母的制备方法Bqt1-Bqt2复合体，其中SUMO标签与Bqt1蛋白的N末端融合。这使我们能够从可溶性级分中纯化Bqt1-Bqt2复合物。在本研究中，我们发现麦芽糖结合蛋白的同系物Athe_0614比SUMO蛋白具有更好的融合伴侣，导致Bqt1-Bqt2复合物的溶解度显着提高。Athe_0614融合伙伴可能会为Bqt1-Bqt2复合物的结构的X射线晶体学分析开辟新的途径。