Thompson R Adam, Spring Alexander M, Sheng Jia, Huang Zhen, Germann Markus W
a Department of Chemistry , Georgia State University , 50 Decatur Street, Atlanta , GA 30303 , USA.
J Biomol Struct Dyn. 2015;33(2):289-97. doi: 10.1080/07391102.2014.880944. Epub 2014 Feb 21.
Selenomethionine incorporation has proven useful in X-ray crystallography of proteins to obtain phase information. In nucleic acids, the introduction of selenium to different positions is beneficial for solving the phase problem as well, but its addition to the 2' position also significantly enhances the crystal formation. The selenium modification in a single nucleotide shows a preference towards 2'-endo sugar puckering, which is in conflict with existing crystal structures where the duplex incorporated 2'-selenium-modified nucleotide is exclusively found in a 3'-endo conformation. Our work provides a rationale why 2'-selenium modifications facilitate crystallization despite this contradictory behavior.
硒代蛋氨酸掺入已被证明在蛋白质的X射线晶体学中用于获取相位信息很有用。在核酸中，将硒引入不同位置也有利于解决相位问题，而且将其添加到2'位置还能显著增强晶体形成。单个核苷酸中的硒修饰表现出对2'-内型糖折叠的偏好，这与现有的晶体结构相冲突，在现有晶体结构中，掺入2'-硒修饰核苷酸的双链体仅以3'-内型构象存在。我们的工作解释了为什么尽管存在这种矛盾行为，2'-硒修饰仍能促进结晶。
