Using barium ions for heavy-atom derivatization and phasing of xylanase II from Trichoderma longibrachiatum
✍ Scribed by Moiseeva, Natalia ;Allaire, Marc
- Book ID
- 104478345
- Publisher
- International Union of Crystallography
- Year
- 2007
- Tongue
- English
- Weight
- 468 KB
- Volume
- 63
- Category
- Article
- ISSN
- 0907-4449
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✦ Synopsis
This paper describes the use of barium chloride to produce a heavy-atom derivative of xylanase II crystals from Trichoderma longibrachiatum, which was obtained either by cocrystallization or soaking. SAD phasing led to interpretable electron-density maps that allowed unambiguous chain tracing. In the best case, with a data set collected at 9.5 keV, 88% of the residues were built, with 83% of the side chains assigned. The barium ions are found to mainly interact with main-chain carbonyl groups and water molecules. It is suggested that barium ions could also be used as a potential anomalous scatterer in the quick cryosoaking procedure for phasing.