Structural insights into mechanism and specificity of the plant protein O-fucosyltransferase SPINDLY.
Zhu, L., Wei, X., Cong, J., Zou, J., Wan, L., Xu, S.(2022) Nat Commun 13: 7424-7424
- PubMed: 36456586 
- DOI: https://doi.org/10.1038/s41467-022-35234-0
- Primary Citation of Related Structures:  
7Y4I - PubMed Abstract: 
Arabidopsis glycosyltransferase family 41 (GT41) protein SPINDLY (SPY) plays pleiotropic roles in plant development. Despite the amino acid sequence is similar to human O-GlcNAc transferase, Arabidopsis SPY has been identified as a novel nucleocytoplasmic protein O-fucosyltransferase. SPY-like proteins extensively exist in diverse organisms, indicating that O-fucosylation by SPY is a common way to regulate intracellular protein functions. However, the details of how SPY recognizes and glycosylates substrates are unknown. Here, we present a crystal structure of Arabidopsis SPY/GDP complex at 2.85 Å resolution. SPY adopts a head-to-tail dimer. Strikingly, the conformation of a 'catalytic SPY'/GDP/'substrate SPY' complex formed by two symmetry-related SPY dimers is captured in the crystal lattice. The structure together with mutagenesis and enzymatic data demonstrate SPY can fucosylate itself and SPY's self-fucosylation region negatively regulates its enzyme activity, reveal SPY's substrate recognition and enzyme mechanism, and provide insights into the glycan donor substrate selection in GT41 proteins.
Organizational Affiliation: 
Hubei Hongshan Laboratory, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.