JenaLib Home    
[JenaLib Home]     [Helix Analysis Home]     [Image Library Entry]     [Sequence, Chains, Units]     [Bending Analysis Entry]     [Bending Classification]   

Analysis of nucleic acid double helix geometry

Title DIMER INITIATION SEQUENCE OF HIV-1LAI GENOMIC RNA: NMR SOLUTION STRUCTURE OF THE EXTENDED DUPLEX
PDB code 1JU1   (PDB summary)
NDB code 1JU1 (NDB atlas)
Duplex length 23 base pairs

Only the nucleic acid double helix part of the structure is analysed here. Small ligands, proteins, and overhanging ends are not taken into account. Information on the complete structure is available at the Image Library Entry page and at the Sequence, Chains, Units page.

Strand 1    5' C1 U2 U3 G4 C5 U6 G7 A8 A9 G10 C11 G12 C13 G14 C15 A16 C17 G18 G19 C20 A21 A22 G23 3'
Strand 2    3' G46 A45 A44 C43 G42 G41 C40 A39 C38 G37 C36 G35 C34 G33 A32 A31 G30 U29 C28 G27 U26 U25 C24 5'

Side view 1 Top view
Side view 1 Top view
Side view 2 3-dimensional interactive models
(Help)
  

RASMOL, CHIME, VRML 2.0, PDB

Side view 2  

Figure 1   Three orthogonal views of the double helix (Help). Residues are colored according to the nucleotide type (Help: Color codes). The curvilinear helical axis (green) was calculated with CURVES. The double helix is oriented with respect to the principle axis of inertia of the curvilinear helical axis (see Help for further explanations). This drawing reveals immediately if there is any bending of the helical axis.


Analysis of helical axis bending


Inter base pair parameters

The six inter base pair parameters (rise, shift, slide, twist, roll, tilt) describe the translational and rotational displacement between neighbouring base pairs. See Help for further explanations.

Plot of inter base pair parameters with respect to global and local helical axes:  PDF,   GIF
(Global parameters from CURVES,  local parameters from CURVES and FREEHELIX)

Table 1.  Inter base pair parameters with respect to the global helical axis, calculated with CURVES.


  Strand 1      Strand 2        riseg          shiftg          slideg          twistg         rollg         tiltg    
    / Å / Å / Å      

C1 G46            
    2.9 -0.2 -0.5 29° 18°
U2 A45            
    2.6 0.3 -0.5 32° -9°
U3 A44            
    2.1 -0.4 -0.6 30°
G4 C43            
    2.8 0.4 0.4 36° -6° -1°
C5 G42            
    2.8 0.6 0.2 40° -0° -2°
U6 G41            
    0.5 -1.5 -1.8 10° 21° -9°
G7 C40            
    2.1 0.9 0.1 29° 39° 20°
A8 A39            
    5.5 -1.1 -0.4 38° -22°
A9 C38            
    3.4 0.4 -0.1 26° -8° 15°
G10 G37            
    2.1 0.7 0.5 32° -17°
C11 C36            
    3.2 0.2 -0.3 32° 11° 31°
G12 G35            
    3.1 -0.0 -0.5 32° 18° -24°
C13 C34            
    2.9 -0.7 -0.3 29°
G14 G33            
    2.7 -0.1 -0.2 22° -8° -8°
C15 A32            
    5.2 1.8 -0.3 38° -9° -8°
A16 A31            
    2.9 -2.2 -0.1 19° 26° -13°
C17 G30            
    1.6 1.1 -1.6 12° 12°
G18 U29            
    3.1 -0.7 0.3 36° 10°
G19 C28            
    2.7 -0.1 0.5 37° -0°
C20 G27            
    2.2 0.5 -0.6 29°
A21 U26            
    3.0 -0.2 -0.3 30° -2°
A22 U25            
    3.8 0.8 -0.4 27° 19° -4°
G23 C24            


Backbone parameters

Table 2.  Selected torsional angles and sugar pucker phase angles describing the conformation of the sugar phosphate backbone. (See Help for further explanations.)


 gamma     epsilon-zeta       pucker        chi      Strand 1     Strand 2      chi        pucker       epsilon-zeta     gamma 

    C3'-endo -100° C1 G46 -165° C2'-endo    
 58°   -114° (BI)             -108° (BI)   57° 
    C3'-endo -139° U2 A45 -152° C4'-exo    
 60°   -111° (BI)             -112° (BI)   59° 
    C3'-endo -156° U3 A44 -155° C3'-endo    
 57°   -117° (BI)             -113° (BI)   57° 
    C3'-endo -144° G4 C43 -153° C3'-endo    
 58°   -120° (BI)             -119° (BI)   57° 
    C4'-exo -145° C5 G42 -153° C3'-endo    
 51°   -116° (BI)             -113° (BI)   176° 
    C3'-endo -138° U6 G41 -162° C3'-endo    
 57°   -109° (BI)             -117° (BI)   -42° 
    C2'-endo -118° G7 C40 -147° C3'-endo    
 178°   -91° (BI)             -149° (BI)   59° 
    C2'-endo -115° A8 A39 -171° C3'-endo    
 56°   -94° (BI)             -117° (BI)   58° 
    C1'-exo -117° A9 C38 -149° C2'-exo    
 177°   -96° (BI)             -115° (BI)   56° 
    C4'-exo -117° G10 G37 -120° C4'-exo    
 57°   -19° (BI)             -101° (BI)   52° 
    C3'-endo -121° C11 C36 -141° C3'-endo    
 56°   -117° (BI)             -110° (BI)   57° 
    C3'-endo -117° G12 G35 -126° C4'-exo    
 51°   -109° (BI)             -114° (BI)   56° 
    C3'-endo -143° C13 C34 -125° C3'-endo    
 56°   -112° (BI)             -26° (BI)   -178° 
    C3'-endo -133° G14 G33 -137° C4'-exo    
 58°   -120° (BI)             37° (BII)   56° 
    C3'-endo -146° C15 A32 -110° C1'-exo    
 60°   -110° (BI)             -10° (BI)   176° 
    C2'-exo -174° A16 A31 -142° C1'-exo    
 -28°   138° (BII)             -92° (BI)   62° 
    C3'-endo -155° C17 G30 -142° C2'-endo    
 66°   -126° (BI)             -112° (BI)   53° 
    C4'-exo -160° G18 U29 -153° C3'-endo    
 56°   -115° (BI)             -117° (BI)   58° 
    C4'-exo -154° G19 C28 -147° C4'-exo    
 57°   -115° (BI)             -117° (BI)   56° 
    C3'-endo -153° C20 G27 -143° C3'-endo    
 59°   -115° (BI)             -119° (BI)   60° 
    C3'-endo -154° A21 U26 -151° C3'-endo    
 58°   -113° (BI)             -119° (BI)   60° 
    C4'-exo -152° A22 U25 -133° C4'-exo    
 62°   -109° (BI)             141° (BII)   63° 
    C2'-endo -165° G23 C24 -56° C4'-exo    


Groove width

Plot of minor groove width:   PDF,   GIF
Plot of major groove width:   PDF,   GIF
(See Help for further explanations.)

Further information

Full output from CURVES  (helical parameters with respect to global and local axes)

Full output from FREEHELIX  (helical parameters with respect to local axis, angles between normal vectors)

Chirality of ribose and phosphate atoms
Check the naming of phosphate and ribose substituents. Recommended for phosphate oxygens and for ribose hydrogens in NMR structures.


Go to    [JenaLib Home]    [Helix Analysis Home]    [Image Library Entry]    [Sequence, Chains, Units]    [Bending Analysis Entry]    [Bending Classification]   

Perl script:    helixparameter.pl  (15 Sep 2016)
Author:    Peter Slickers  (slickers@leibniz-fli.de),  IMB Jena,  Germany