DSSR-enabled G4 identification/annotation: PDB entry 5nyt
Summary information and primary citation
- PDB-id
- 5nyt
- Class
- DNA
- Method
- NMR
- Summary
- M2 g-quadruplex 20 wt% ethylene glycol
- Reference
- Trajkovski M, Endoh T, Tateishi-Karimata H, Ohyama T, Tanaka S, Plavec J, Sugimoto N (2018): "Pursuing origins of (poly)ethylene glycol-induced G-quadruplex structural modulations." Nucleic Acids Res., 46, 4301-4315. doi: 10.1093/nar/gky250.
- Abstract
- Molecular crowding conditions provided by high concentration of cosolutes are utilized for characterization of biomolecules in cell-mimicking environment and development of drug-delivery systems. In this context, (poly)ethylene glycols are often used for studying non-canonical DNA structures termed G-quadruplexes, which came into focus by emerging structural biology findings and new therapeutic drug design approaches. Recently, several reports were made arguing against using (poly)ethylene glycols in role of molecular crowding agents due to their direct impact on DNA G-quadruplex stability and topology. However, the available data on structural details underlying DNA interaction is very scarce and thus limits in-depth comprehension. Herein, structural and thermodynamic analyses were strategically combined to assess G-quadruplex-cosolute interactions and address previously reported variances regarding the driving forces of G-rich DNA structural transformations under molecular crowding conditions. With the use of complementary (CD, NMR and UV) spectroscopic methods and model approach we characterized DNA G-quadruplex in the presence of the smallest and one of the largest typically used (poly)ethylene glycols. Dehydration effect is the key contributor to ethylene-glycol-induced increased stability of the G-quadruplex, which is in the case of the large cosolute mainly guided by the subtle direct interactions between PEG 8000 and the outer G-quartet regions.
- G4 notes
- 3 G-tetrads, 1 G4 helix, 1 G4 stem, UUUU, parallel, 4+0, 3(-P-P-P)
Cartoon-block schematics in six views (download the tarball)
List of 3 G-tetrads
1 glyco-bond=---- sugar=---- groove=---- planarity=0.129 type=planar O+ nts=4 GGGG A.DG3,A.DG8,A.DG12,A.DG17 2 glyco-bond=---- sugar=---- groove=---- planarity=0.207 type=other O+ nts=4 GGGG A.DG4,A.DG9,A.DG13,A.DG18 3 glyco-bond=---- sugar=---- groove=---- planarity=0.228 type=other O+ nts=4 GGGG A.DG5,A.DG10,A.DG14,A.DG19
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-tetrads, INTRA-molecular, with 1 stem
|
1 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG8,A.DG12,A.DG17 2 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG4,A.DG9,A.DG13,A.DG18 3 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG5,A.DG10,A.DG14,A.DG19 step#1 pm(>>,forward) area=15.40 rise=3.41 twist=24.4 step#2 pm(>>,forward) area=11.69 rise=3.36 twist=28.8 strand#1 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG3,A.DG4,A.DG5 strand#2 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG8,A.DG9,A.DG10 strand#3 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG12,A.DG13,A.DG14 strand#4 DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG17,A.DG18,A.DG19 |
| 2 stacking diagrams | |
|
1 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG8,A.DG12,A.DG17 |
|
2 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG4,A.DG9,A.DG13,A.DG18 |
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-tetrads, 3 loops, INTRA-molecular, UUUU, parallel, 4+0, 3(-P-P-P)
|
1 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG3,A.DG8,A.DG12,A.DG17 2 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG4,A.DG9,A.DG13,A.DG18 3 glyco-bond=---- sugar=---- groove=---- WC-->Major O+ nts=4 GGGG A.DG5,A.DG10,A.DG14,A.DG19 step#1 pm(>>,forward) area=15.40 rise=3.41 twist=24.4 step#2 pm(>>,forward) area=11.69 rise=3.36 twist=28.8 strand#1 U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG3,A.DG4,A.DG5 strand#2 U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG8,A.DG9,A.DG10 strand#3 U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG12,A.DG13,A.DG14 strand#4 U DNA glyco-bond=--- sugar=--- nts=3 GGG A.DG17,A.DG18,A.DG19 loop#1 type=propeller strands=[#1,#2] nts=2 AC A.DA6,A.DC7 loop#2 type=propeller strands=[#2,#3] nts=1 C A.DC11 loop#3 type=propeller strands=[#3,#4] nts=2 CA A.DC15,A.DA16 |