title: The importance of fitting in: conformational preference of selenium 2' modifications in nucleosides and helical structures.
abstract: 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.
authors.affiliation: a Department of Chemistry , Georgia State University , 50 Decatur Street, Atlanta , GA 30303 , USA.
authors.forename: R Adam
authors.initials: RA
authors.lastname: Thompson
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Spring
authors.forename: Jia
authors.initials: J
authors.lastname: Sheng
authors.forename: Zhen
authors.initials: Z
authors.lastname: Huang
authors.forename: Markus W
authors.initials: MW
authors.lastname: Germann
mesh_terms: D001483:Base Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D009705:Nucleosides / Q000737:chemistry*; D016566:Organoselenium Compounds / Q000737:chemistry*; D044366:Transition Temperature
chemical_list: D009705:Nucleosides; D016566:Organoselenium Compounds; D004247:DNA
keywords: DNA structure; NMR; conformational bias; selenium; sugar puckering