6VLQ

Hop phytocystatin in space group P22121

6VLQ の概要

• エントリーDOI: 10.2210/pdb6vlq/pdb
• 分子名称: Hop1, SULFATE ION (3 entities in total)
• 機能のキーワード: cystatin, domain-swap, inhibitor, hop, protein binding
• 由来する生物種: Humulus lupulus (European hop)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 11354.82

構造登録者

Valadares, F.F.,Moura, G.T. (登録日: 2020-01-24, 公開日: 2020-10-14, 最終更新日: 2023-10-11)

主引用文献

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

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: 32947025
DOI: 10.1016/j.bbapap.2020.140541

実験手法

X-RAY DIFFRACTION (1.799 Å)