SWI/SNF remodelers play a key role in regulating chromatin architecture and gene expression. Here, we report the cryo-EM structure of the Saccharomyces cerevisiae Swi/Snf complex in a nucleosome-free state. The structure consists of a stable triangular base module and a flexible Arp module. The conserved subunits Swi1 and Swi3 form the backbone of the complex and closely interact with other components. Snf6, which is specific for yeast Swi/Snf complex, stabilizes the binding of the ATPase-containing subunit Snf2 to the base module. Comparison of the yeast Swi/Snf and RSC complexes reveals conserved structural features that govern the assembly and function of these two subfamilies of chromatin remodelers. Our findings complement those from recent structures of the yeast and human chromatin remodelers and provide further insights into the assembly and function of the SWI/SNF remodelers.

SWI/SNF 重塑剂在调节染色质结构和基因表达方面发挥着关键作用。在这里，我们报告了酿酒酵母的冷冻电镜结构Swi/Snf 复合物处于无核小体状态。该结构由一个稳定的三角形底座模块和一个灵活的Arp模块组成。保守的亚基 Swi1 和 Swi3 形成复合物的骨架并与其他组分密切相互作用。Snf6 对酵母 Swi/Snf 复合物具有特异性，可稳定含有 ATP 酶的亚基 Snf2 与基本模块的结合。酵母 Swi/Snf 和 RSC 复合物的比较揭示了控制这两个染色质重塑子亚家族的组装和功能的保守结构特征。我们的研究结果补充了酵母和人类染色质重塑器的最新结构，并为 SWI/SNF 重塑器的组装和功能提供了进一步的见解。