CRYSTAL STRUCTURE OF COLICIN IA DETERMINATION BY CRYOCRYSTALLOGRAPHY

使用1)闪速冻结和2)大幅面MAR成像板 光束线7-1，分辨率已从之前的2.35 E延长到2.35 E 2.8E的极限。该2.8E数据集是从冻结晶体获得的 分辨率受到较小的MAR成像板的限制。冰冻 已经消除了困扰早期实验的辐射损害。一个 广泛的冷冻液和人造母液 检查过了。用锂取代硫酸铵/柠檬酸盐缓冲液 硫酸盐/醋酸盐缓冲液成功。这种人造母液 将用于重原子浸泡。经过筛选后的低分辨率 在实验室里，有希望的候选人将被带到SSRL。 到目前为止最好的候选者是CH3HgCl；单位点半胱氨酸突变体将 也可利用(天然不含半胱氨酸)。

Using 1) flash-freezing and 2) large-format MAR imaging plate at beamline 7-1, resolution has been extended to 2.35 E from previous limit of 2.8 E. This 2.8 E data set was obtained from frozen crystals with resolution limited by the smaller MAR imaging plates. Freezing has eliminated the radiation damage plaguing earlier experiments. A wide range of cryosolvents and artificial mother liquors were examined. Replacement of ammonium sulfate/citrate buffer by lithium sulfate/acetate buffer was successful. This artificial mother liquor will be used for heavy atom soaks. After screening low-resolution data in the lab, the promising candidates will be brought to SSRL. The best candidate to date is CH3HgCl; single-site Cys mutants will also be utilized (native has no cysteines).