Summary information

PDB id
1s9l
Class
RNA
Method
NMR
Summary
NMR solution structure of a parallel lna quadruplex
Reference
Randazzo A, Esposito V, Ohlenschlager O, Ramachandran R, Mayola L (2004): "NMR solution structure of a parallel LNA quadruplex." Nucleic Acids Res., 32, 3083-3092. doi: 10.1093/nar/gkh629.
Abstract
The solution structure of a locked nucleic acid (LNA) quadruplex, formed by the oligomer d(TGGGT), containing only conformationally restricted LNA residues is reported. NMR and CD spectroscopy, as well as molecular dynamics and mechanic calculations, has been used to characterize the complex. The molecule adopts a parallel stranded conformation with a 4-fold rotational symmetry, showing a right-handed helicity and the guanine residues in an almost planar conformation with three well-defined G-tetrads. The thermal stability of Q-LNA has been found to be comparable with that of [r(UGGGU)]4, while a T(m) increment of 20 degrees C with respect to the corresponding DNA quadruplex structure [d(TGGGT)]4 has been observed. The structural features of the LNA quadruplex reported here may open new perspectives for the biological application of LNAs as novel versatile tools to design aptamer or catalyst oligonucleotides.
G4 notes
3 G-tetrads, 1 G4 helix, 1 G4 stem, parallel(4+0), UUUU

Base-block schematics in six views

PyMOL session file PDB file View in 3Dmol.js

List of 3 G-tetrads

 1 glyco-bond=---- sugar=3333 groove=---- planarity=0.227 type=other  nts=4 gggg A.LCG2,C.LCG12,D.LCG17,B.LCG7
 2 glyco-bond=---- sugar=3333 groove=---- planarity=0.208 type=other  nts=4 gggg A.LCG3,C.LCG13,D.LCG18,B.LCG8
 3 glyco-bond=---- sugar=3333 groove=---- planarity=0.191 type=other  nts=4 gggg A.LCG4,C.LCG14,D.LCG19,B.LCG9

List of 1 G4-helix

In DSSR, a G4-helix is defined by stacking interactions of G-tetrads, regardless of backbone connectivity, and may contain more than one G4-stem.

Helix#1, 3 G-tetrad layers, inter-molecular, with 1 stem

 1  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG2,C.LCG12,D.LCG17,B.LCG7
 2  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG3,C.LCG13,D.LCG18,B.LCG8
 3  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG4,C.LCG14,D.LCG19,B.LCG9
  step#1  pm(>>,forward)  area=15.69 rise=3.49 twist=28.9
  step#2  pm(>>,forward)  area=15.90 rise=3.49 twist=27.8
  strand#1 --- glyco-bond=--- sugar=333 nts=3 ggg A.LCG2,A.LCG3,A.LCG4
  strand#2 --- glyco-bond=--- sugar=333 nts=3 ggg C.LCG12,C.LCG13,C.LCG14
  strand#3 --- glyco-bond=--- sugar=333 nts=3 ggg D.LCG17,D.LCG18,D.LCG19
  strand#4 --- glyco-bond=--- sugar=333 nts=3 ggg B.LCG7,B.LCG8,B.LCG9

Download PDB file
Interactive view in 3Dmol.js

2 stacking diagrams
 1  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG2,C.LCG12,D.LCG17,B.LCG7
2 glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG3,C.LCG13,D.LCG18,B.LCG8
step#1 pm(>>,forward) area=15.69 rise=3.49 twist=28.9

Download PDB file
Interactive view in 3Dmol.js

 2  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG3,C.LCG13,D.LCG18,B.LCG8
3 glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG4,C.LCG14,D.LCG19,B.LCG9
step#2 pm(>>,forward) area=15.90 rise=3.49 twist=27.8

Download PDB file
Interactive view in 3Dmol.js

List of 1 G4-stem

In DSSR, a G4-stem is defined as a G4-helix with backbone connectivity. Bulges are also allowed along each of the four strands.

Stem#1, 3 G-tetrad layers, 0 loops, inter-molecular, UUUU, parallel, parallel(4+0)

 1  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG2,C.LCG12,D.LCG17,B.LCG7
 2  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG3,C.LCG13,D.LCG18,B.LCG8
 3  glyco-bond=---- sugar=3333 groove=---- WC-->Major nts=4 gggg A.LCG4,C.LCG14,D.LCG19,B.LCG9
  step#1  pm(>>,forward)  area=15.69 rise=3.49 twist=28.9
  step#2  pm(>>,forward)  area=15.90 rise=3.49 twist=27.8
  strand#1  U --- glyco-bond=--- sugar=333 nts=3 ggg A.LCG2,A.LCG3,A.LCG4
  strand#2  U --- glyco-bond=--- sugar=333 nts=3 ggg C.LCG12,C.LCG13,C.LCG14
  strand#3  U --- glyco-bond=--- sugar=333 nts=3 ggg D.LCG17,D.LCG18,D.LCG19
  strand#4  U --- glyco-bond=--- sugar=333 nts=3 ggg B.LCG7,B.LCG8,B.LCG9

Download PDB file
Interactive view in 3Dmol.js