Download MendeleyProline Isomerization and Molten Globular Property of TgPDCD5 Secreted from Toxoplasma gondii Confers Its Regulation of Heparin Sulfate Binding.
Lin, G.M., Yu, T.A., Chang, C.F., Hsu, C.H.(2024) JACS Au 4: 1763-1774
- PubMed: 38818051
- DOI: https://doi.org/10.1021/jacsau.3c00577
- Primary Citation of Related Structures:
8I25, 8I26 - PubMed Abstract:
Toxoplasmosis, caused by Toxoplasma gondii , poses risks to vulnerable populations. TgPDCD5, a secreted protein of T. gondii , induces apoptosis through heparan sulfate-mediated endocytosis. The entry mechanism of TgPDCD5 has remained elusive. Here, we present the solution structure of TgPDCD5 as a helical bundle with an extended N-terminal helix, exhibiting molten globule characteristics. NMR perturbation studies reveal heparin/heparan sulfate binding involving the heparan sulfate/heparin proteoglycans-binding motif and the core region, influenced by proline isomerization of P107 residue. The heterogeneous proline recruits a cyclophilin TgCyp18, accelerating interconversion between conformers and regulating heparan/heparin binding. These atomic-level insights elucidate the binary switch's functionality, expose novel heparan sulfate-binding surfaces, and illuminate the unconventional cellular entry of pathogenic TgPDCD5.
Organizational Affiliation:
Department of Agricultural Chemistry, National Taiwan University, Taipei 10617, Taiwan.
