title: Covalent incorporation of selenium into oligonucleotides for X-ray crystal structure determination via MAD: proof of principle. Multiwavelength anomalous dispersion.
abstract: Selenium was incorporated into an oligodeoxynucleotide in the form of 2'-methylseleno-uridine (U(Se)). The X-ray crystal structure of the duplex left open bracket d(GCGTA)U(Se)d(ACGC) right open bracket (2) was determined by the multiwavelength anomalous dispersion (MAD) technique and refined to a resolution of 1.3 A, demonstrating that selenium can selectively substitute oxygen in DNA and that the resulting compounds are chemically stable. Since derivatization at the 2'-alpha-position with selenium does not affect the preference of the sugar for the C3'-endo conformation, this strategy is suitable for incorporating selenium into RNA. The availability of selenium-containing nucleic acids for crystallographic phasing offers an attractive alternative to the commonly used halogenated pyrimidines.
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA.
authors.forename: Marianna
authors.initials: M
authors.lastname: Teplova
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Wilds
authors.forename: Zdzislaw
authors.initials: Z
authors.lastname: Wawrzak
authors.forename: Valentina
authors.initials: V
authors.lastname: Tereshko
authors.forename: Quan
authors.initials: Q
authors.lastname: Du
authors.forename: Nicolas
authors.initials: N
authors.lastname: Carrasco
authors.forename: Zhen
authors.initials: Z
authors.lastname: Huang
authors.forename: Martin
authors.initials: M
authors.lastname: Egli
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D006358:Hot Temperature; D008958:Models, Molecular; D009691:Nucleic Acid Denaturation; D009841:Oligonucleotides / Q000737:chemistry*; D016566:Organoselenium Compounds / Q000737:chemistry*; D011336:Probability; D013052:Spectrometry, X-Ray Emission; D014529:Uridine / Q000737:chemistry
chemical_list: D009841:Oligonucleotides; D016566:Organoselenium Compounds; D014529:Uridine