Structural insights into the biochemical mechanism of the E2/E3 hybrid enzyme UBE2O

Hao Huang; Wenning Zhu; Bin Huang; Ziyang Fu; Yuxian Xiong; Dan Cao; Yuxin Ye; Qing Chang; Wenqi Li; Long Li; Huan Zhou; Xiaogang Niu; Wei Zhang

doi:10.1016/j.str.2024.12.002

Structural insights into the biochemical mechanism of the E2/E3 hybrid enzyme UBE2O

Structure. 2024 Dec 24:S0969-2126(24)00537-9. doi: 10.1016/j.str.2024.12.002. Online ahead of print.

Authors

Hao Huang¹, Wenning Zhu², Bin Huang², Ziyang Fu², Yuxian Xiong², Dan Cao², Yuxin Ye², Qing Chang³, Wenqi Li³, Long Li⁴, Huan Zhou⁵, Xiaogang Niu⁶, Wei Zhang⁷

Affiliations

¹ State Key Laboratory of Chemical Oncogenomics, Laboratory of Structural Biology and Drug Discovery, Laboratory of Ubiquitination and Targeted Therapy, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China; Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen, Guangdong 518132, China. Electronic address: [email protected].
² State Key Laboratory of Chemical Oncogenomics, Laboratory of Structural Biology and Drug Discovery, Laboratory of Ubiquitination and Targeted Therapy, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
³ Beijing Advanced Innovation Center for Structural Biology, Technology Center for Protein Research, School of Life Sciences, Tsinghua University, Beijing 100084, China.
⁴ Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen, Guangdong 518132, China.
⁵ Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, China.
⁶ College of Chemistry and Molecular Engineering, Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing 100871, China.
⁷ Department of Molecular and Cellular Biology, College of Biological Science, University of Guelph, Guelph, ON, Canada.

PMID: 39740670
DOI: 10.1016/j.str.2024.12.002

Abstract

The E2/E3 hybrid enzyme UBE2O plays important roles in key biological events, but its autoubiquitination mechanism remains largely unclear. In this study, we determined the crystal structures of full-length (FL) UBE2O from Trametes pubescens (tp) and its ubiquitin-conjugating (UBC) domain. The dimeric FL-tpUBE2O structure revealed interdomain interactions between the conserved regions (CR1-CR2) and UBC. The dimeric intermolecular and canonical ubiquitin/UBC interactions are mechanistically important for UBE2O functions in catalyzing the formation of free polyubiquitin chains and substrate ubiquitination. Beyond dimerization, autoubiquitination within the CR1-CR2 domain also regulates tpUBE2O activity. Additionally, we show that tpUBE2O catalyzes the formation of all seven types of polyubiquitin chains in vitro. The CR1-CR2/UBC and canonical ubiquitin/UBC interactions are important for the polyubiquitination of AMP-activated protein kinase α2 (AMPKα2) by human UBE2O (hUBE2O), which leads to tumorigenesis. These structural insights lay the groundwork for understanding UBE2O's mechanisms and developing structure-based therapeutics targeting UBE2O.

Keywords: AMPKα2; E2 enzyme; E2/E3 hybrid enzyme; NMR; UBC; UBE2O; cancer; dimer; structure; ubiquitin.