Cryo-EM Structures of Smc5/6 in Multiple States Reveal Its Assembly and Functional Mechanisms

Overview

Journal Nat Struct Mol Biol

Specialties Cell Biology
Molecular Biology

Date 2024 Jun 18

PMID 38890552

Authors

Qian Li

Jun Zhang

Cory Haluska

Xiang Zhang

Lei Wang

Guangfeng Liu

Zhaoning Wang

Duo Jin

Tong Cheng

Hongxia Wang

Yuan Tian

Xiangxi Wang

Lei Sun

Xiaolan Zhao

Zhenguo Chen

Lanfeng Wang

Affiliations

Soon will be listed here.

Abstract

Smc5/6 is a member of the eukaryotic structural maintenance of chromosomes (SMC) family of complexes with important roles in genome maintenance and viral restriction. However, limited structural understanding of Smc5/6 hinders the elucidation of its diverse functions. Here, we report cryo-EM structures of the budding yeast Smc5/6 complex in eight-subunit, six-subunit and five-subunit states. Structural maps throughout the entire length of these complexes reveal modularity and key elements in complex assembly. We show that the non-SMC element (Nse)2 subunit supports the overall shape of the complex and uses a wedge motif to aid the stability and function of the complex. The Nse6 subunit features a flexible hook region for attachment to the Smc5 and Smc6 arm regions, contributing to the DNA repair roles of the complex. Our results also suggest a structural basis for the opposite effects of the Nse1-3-4 and Nse5-6 subcomplexes in regulating Smc5/6 ATPase activity. Collectively, our integrated structural and functional data provide a framework for understanding Smc5/6 assembly and function.

Citing Articles

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