SMC (structural maintenance of chromosomes) protein complexes are an evolutionarily conserved family of motor proteins that hold sister chromatids together and fold genomes throughout the cell cycle by DNA loop extrusion. These complexes play a key role in a variety of functions in the packaging and regulation of chromosomes, and they have been intensely studied in recent years. Despite their importance, the detailed molecular mechanism for DNA loop extrusion by SMC complexes remains unresolved. Here, we describe the roles of SMCs in chromosome biology and particularly review in vitro single-molecule studies that have recently advanced our understanding of SMC proteins. We describe the mechanistic biophysical aspects of loop extrusion that govern genome organization and its consequences.

中文翻译：

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使用 SMC 复合物循环基因组

SMC（染色体结构维护）蛋白复合物是一个进化上保守的运动蛋白家族，它将姐妹染色单体固定在一起，并通过 DNA 环挤压在整个细胞周期中折叠基因组。这些复合物在染色体包装和调节的多种功能中发挥着关键作用，近年来得到了深入的研究。尽管它们很重要，但 SMC 复合物挤出 DNA 环的详细分子机制仍未解决。在这里，我们描述了 SMC 在染色体生物学中的作用，特别回顾了最近增进我们对 SMC 蛋白理解的体外单分子研究。我们描述了控制基因组组织及其后果的环挤出的机械生物物理方面。