Structure of a d(TGGGGT) quadruplex crystallized in the presence of Li+ ions.

Acta Crystallogr D Biol Crystallogr 2007 Jun 15;63(Pt 6):682-8. Epub 2007 May 15.

Laboratoire de BioCristallographie, Institut de Biologie et Chimie des Protéines, CNRS-UCBL, UMR 5086, IFR128 BioSciences Lyon-Gerland, 7 Passage du Vercors, 69007 Lyon, France.

A parallel 5'-d(TGGGGT)-3' quadruplex was formed in Na(+) solution and crystallized using lithium sulfate as the main precipitating agent. The X-ray structure was determined to 1.5 A resolution in space group P2(1) by molecular replacement. The asymmetric unit consists of a characteristic motif of two quadruplexes stacked at their 5' ends. All nucleotides are clearly defined in the density and could be positioned. A single bound Li(+) ion is observed at the surface of the column formed by the two joined molecules. Thus, this small alkali metal ion appears to be unsuitable as a replacement for the Na(+) ion in the central channel of G-quartets, unlike K(+) or Tl(+) ions. A well conserved constellation of water molecules is observed in the grooves of the dimeric structure.

Download full-text PDF

Source
http://dx.doi.org/10.1107/S0907444907013315DOI Listing
June 2007
17 Reads

Publication Analysis

Top Keywords

bound li+
4
single bound
4
positioned single
4
density positioned
4
li+ ion
4
ion observed
4
formed joined
4
column formed
4
surface column
4
observed surface
4
defined density
4
clearly defined
4
unit consists
4
asymmetric unit
4
replacement asymmetric
4
molecular replacement
4
consists characteristic
4
characteristic motif
4
nucleotides clearly
4
ends nucleotides
4

Similar Publications