8ENA

Thaumatin native-SAD structure determined at 5 keV with a helium environmet

8ENA の概要

• エントリーDOI: 10.2210/pdb8ena/pdb
• 分子名称: Thaumatin-1 (2 entities in total)
• 機能のキーワード: anomalous diffration, native sad, low energy, helium path, plant protein
• 由来する生物種: Thaumatococcus daniellii
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 22227.06

構造登録者

Karasawa, A.,Andi, B.,Ruchs, M.R.,Shi, W.,McSweeney, S.,Hendrickson, W.A.,Liu, Q. (登録日: 2022-09-29, 公開日: 2022-11-02, 最終更新日: 2024-11-20)

主引用文献

Karasawa, A.,Andi, B.,Fuchs, M.R.,Shi, W.,McSweeney, S.,Hendrickson, W.A.,Liu, Q.
Multi-crystal native-SAD phasing at 5 keV with a helium environment.
Iucrj, 9:768-777, 2022

PubMed Abstract: structure determination from single-wavelength anomalous diffraction using native sulfur or phospho-rus in biomolecules (native-SAD) is an appealing method to mitigate the labor-intensive production of heavy-atom derivatives and seleno-methio-nyl substitutions. The native-SAD method is particularly attractive for membrane proteins, which are difficult to produce and often recalcitrant to grow into decent-sized crystals. Native-SAD uses lower-energy X-rays to enhance anomalous signals from sulfur or phospho-rus. However, at lower energies, the scattering and absorption of air contribute to the background noise, reduce the signals and are thus adverse to native-SAD phasing. We have previously demonstrated native-SAD phasing at an energy of 5 keV in air at the NSLS-II FMX beamline. Here, the use of a helium path developed to reduce both the noise from background scattering and the air absorption of the diffracted X-ray beam are described. The helium path was used for collection of anomalous diffraction data at 5 keV for two proteins: thaumatin and the membrane protein TehA. Although anomalous signals from each individual crystal are very weak, robust anomalous signals are obtained from data assembled from micrometre-sized crystals. The thaumatin structure was determined from 15 microcrystals and the TehA structure from 18 microcrystals. These results demonstrate the usefulness of a helium environment in support of native-SAD phasing at 5 keV.

PubMed: 36381147
DOI: 10.1107/S205225252200971X

実験手法

X-RAY DIFFRACTION (2.5 Å)