ANS complex of St John's wort PR-10 protein with 28 copies in the asymmetric unit: A fiendish combination of pseudosymmetry with tetartohedral twinning
Hyp-1, a pathogenesis-related class 10 (PR-10) protein from St John's wort (Hypericum perforatum), was crystallized in complex with the fluorescent probe 8-anilino-1-naphthalene sulfonate (ANS). The highly pseudosymmetric crystal has 28 unique protein molecules arranged in columns with sevenfold translational noncrystallographic symmetry (tNCS) along c and modulated X-ray diffraction with intensity crests at l = 7n and l = 7n ± 3. The translational NCS is combined with pseudotetragonal rotational NCS. The crystal was a perfect tetartohedral twin, although detection of twinning was severely hindered by the pseudosymmetry. The structure determined at 2.4 Å resolution reveals that the Hyp-1 molecules (packed as β-sheet dimers) have three novel ligand-binding sites (two internal and one in a surface pocket), which was confirmed by solution studies. In addition to 60 Hyp-1-docked ligands, there are 29 interstitial ANS molecules distributed in a pattern that violates the arrangement of the protein molecules and is likely to be the generator of the structural modulation. In particular, whenever the stacked Hyp-1 molecules are found closer together there is an ANS molecule bridging them.
- Polish Academy of Sciences, Poznan (Poland). Center for Biocrystallogrphic Research.
- Argonne National Lab., Argonne, IL (United States). Synchrotron Radiation Research Section.
- Poznan Univ. of Medical Sciecnes, Poznan (Poland). Dept. of Organic Chemistry.
- Univ. of Cambridge, Cambridge (England). Dept. of Haematology.
- Polish Academy of Sciences, Poznan (Poland). Center for Biocrystallogrphic Research; A. Mickiewicz Univ., Poznan (Poland). Dept. of Crystallography.
- Publication Date:
- OSTI Identifier:
- Grant/Contract Number:
- Accepted Manuscript
- Journal Name:
- Acta Crystallographica. Section D: Biological Crystallography (Online)
- Additional Journal Information:
- Journal Name: Acta Crystallographica. Section D: Biological Crystallography (Online); Journal Volume: 71; Journal Issue: 4; Journal ID: ISSN 1399-0047
- International Union of Crystallography
- Research Org:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Org:
- Country of Publication:
- United States
- 59 BASIC BIOLOGICAL SCIENCES pathogenesis-related class 10 protein; St John’s wort; Hypericum perforatum; 8-anilino-1-naphthalene sulfonate