6VLP
Hop phytocystatin in space group C2221
Summary for 6VLP
| Entry DOI | 10.2210/pdb6vlp/pdb |
| Descriptor | Hop1, TRIS(HYDROXYETHYL)AMINOMETHANE, SULFATE ION, ... (4 entities in total) |
| Functional Keywords | cystatin, domain-swap, inhibitor, hop, protein binding |
| Biological source | Humulus lupulus (European hop) |
| Total number of polymer chains | 1 |
| Total formula weight | 11710.16 |
| Authors | Valadares, N.F.,Moura, G.T. (deposition date: 2020-01-24, release date: 2020-10-14, Last modification date: 2023-10-11) |
| Primary citation | Moura, G.T.,Souza, A.A.,Garay, A.V.,Freitas, S.M.,Valadares, N.F. Crystal structure and physicochemical characterization of a phytocystatin from Humulus lupulus: Insights into its domain-swapped dimer Biochim Biophys Acta Proteins Proteom, 1869:140541-140541, 2020 Cited by PubMed Abstract: Phytocystatins are a family of plant cysteine-protease inhibitors of great interest due to their biotechnological application in culture improvement. It was shown that their expression in plants increases resistance to herbivory by insects and improves tolerance to both biotic and abiotic stress factors. In this work, owing to the economical relevance of the source organism, a phytocystatin from hop (Humulus lupulus), Hop1, was produced by heterologous expression in E. coli Lemo21 (DE3) cultivated in auto-inducing ZYM-5052 medium and purified by immobilized metal ion affinity and size exclusion chromatography. Thermal denaturation assays by circular dichroism showed that Hop1 exhibited high melting temperatures ranging from 82 °C to 85 °C and high thermal stability at a wide pH range, with ΔG's higher than 12 kcal/mol. At 20 °C and pH 7.6, the dimeric conformation of the protein is favored according to size exclusion chromatography and analytical ultracentrifugation data, although monomers and higher order oligomers could still be detected in a lesser extent. The crystal structure of Hop1 was solved in the space groups P 2 2 2 and C 2 2 2 at resolutions of 1.80 Å and 1.68 Å, respectively. In both models, Hop1 is folded as a domain-swapped dimer where the first inhibitory loop undergoes a significant structural change and interacts with their equivalent from the other monomer forming a long antiparallel beta strand, leading to loss of inhibitory activity. PubMed: 32947025DOI: 10.1016/j.bbapap.2020.140541 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.681 Å) |
Structure validation
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