Crystal structure of potato 14-3-3 protein St14f revealed the importance of helix I in StFDL1 recognition.
Harada, K.I., Furuita, K., Yamashita, E., Taoka, K.I., Tsuji, H., Fujiwara, T., Nakagawa, A., Kojima, C.(2022) Sci Rep 12: 11596-11596
- PubMed: 35804047 
- DOI: https://doi.org/10.1038/s41598-022-15505-y
- Primary Citation of Related Structures:  
7XBQ - PubMed Abstract: 
In potato (Solanum tuberosum L.), 14-3-3 protein forms a protein complex with the FLOWERING LOCUS T (FT)-like protein StSP6A and the FD-like protein StFDL1 to activate potato tuber formation. Eleven 14-3-3 isoforms were reported in potato, designated as St14a-k. In this study, the crystal structure of the free form of St14f was determined at 2.5 Å resolution. Three chains were included in the asymmetric unit of the St14f free form crystal, and the structural deviation among the three chain structures was found on the C-terminal helix H and I. The St14f free form structure in solution was also investigated by nuclear magnetic resonance (NMR) residual dipolar coupling analysis, and the chain B in the crystal structure was consistent with NMR data. Compared to other crystal structures, St14f helix I exhibited a different conformation with larger B-factor values. Larger B-factor values on helix I were also found in the 14-3-3 free form structure with higher solvent contents. The mutation in St14f Helix I stabilized the complex with StFDL1. These data clearly showed that the flexibility of helix I of 14-3-3 protein plays an important role in the recognition of target protein.
Organizational Affiliation: 
Institute for Protein Research, Osaka University, Suita, Osaka, Japan.