Goulet Adeline, Vestergaard Gisle, Felisberto-Rodrigues Catarina, Campanacci Valérie, Garrett Roger A, Cambillau Christian, Ortiz-Lombardía Miguel
Architecture et Fonction des Macromolécules Biologiques UMR 6098, CNRS, Universités d'Aix-Marseille I et II, Case 932, 163 Avenue de Luminy, 13288 Marseille CEDEX 9, France.
Acta Crystallogr D Biol Crystallogr. 2010 Mar;66(Pt 3):304-8. doi: 10.1107/S0907444909051798. Epub 2010 Feb 12.
The structure of a 14 kDa structural protein from Acidianus two-tailed virus (ATV) was solved by single-wavelength anomalous diffraction (SAD) phasing using X-ray data collected at 2.0 A wavelength. Although the anomalous signal from methionine sulfurs was expected to suffice to solve the structure, one chloride ion turned out to be essential to achieve phasing. The minimal data requirements and the relative contributions of the Cl and S atoms to phasing are discussed. This work supports the feasibility of a systematic approach for the solution of protein crystal structures by SAD based on intrinsic protein light atoms along with associated chloride ions from the solvent. In such cases, data collection at long wavelengths may be a time-efficient alternative to selenomethionine substitution and heavy-atom derivatization.
利用在2.0埃波长下收集的X射线数据，通过单波长反常散射（SAD）相位法解析了嗜酸热栖双尾病毒（ATV）14 kDa结构蛋白的结构。尽管预期甲硫氨酸硫的反常信号足以解析结构，但结果表明一个氯离子对于实现相位解析至关重要。讨论了最小数据要求以及氯原子和硫原子对相位解析的相对贡献。这项工作支持了一种基于蛋白质固有轻原子以及来自溶剂的相关氯离子，通过SAD系统解析蛋白质晶体结构的方法的可行性。在这种情况下，长波长数据收集可能是替代硒代甲硫氨酸取代和重原子衍生化的一种省时方法。
