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

Analysis of nucleic acid double helix geometry

PDB code 4E5C   (PDB summary)
Duplex length 19 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' G1 G2 C3 G4 G5 C6 G7 G8 C9 G10 G11 C12 U13 G14 C15 U16 G17 C18 C19 3'
Strand 2    3' C19 C18 G17 U16 C15 G14 U13 C12 G11 G10 C9 G8 G7 C6 G5 G4 C3 G2 G1 5'

Warning
  1 base(s) in syn conformation detected.
  Helix parameters and curvilinear axis from CURVES are meaningless (see Help).


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.


Backbone parameters

Table 1.  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 

    C2'-exo -176° G1 C19 -162° C3'-endo    
 57°   -82° (BI)             -81° (BI)   60° 
    C3'-endo -164° G2 C18 -165° C3'-endo    
 47°   -81° (BI)             -78° (BI)   50° 
    C3'-endo -160° C3 G17 -162° C3'-endo    
 -178°   -102° (BI)             -77° (BI)   54° 
    C3'-endo 179° G4 U16 -166° C3'-endo    
 49°   -70° (BI)             -76° (BI)   56° 
    C3'-endo -172° G5 C15 -165° C3'-endo    
 58°   -90° (BI)             -97° (BI)   74° 
    C3'-endo -165° C6 G14 -171° C3'-endo    
 80°   -100° (BI)             -83° (BI)   53° 
    C3'-endo -179° G7 U13 -160° C3'-endo    
 43°   -76° (BI)             -75° (BI)   48° 
    C3'-endo -164° G8 C12 -164° C3'-endo    
 50°   -81° (BI)             -81° (BI)   54° 
    C3'-endo -164° C9 G11 -167° C3'-endo    
 67°   -90° (BI)             -93° (BI)   174° 
    C3'-endo -168° G10 G10 10° C3'-endo    
 59°   -94° (BI)             -76° (BI)   51° 
    C3'-endo -167° G11 C9 -159° C3'-endo    
 57°   -72° (BI)             -78° (BI)   52° 
    C3'-endo -162° C12 G8 -166° C3'-endo    
 58°   -80° (BI)             -76° (BI)   -178° 
    C3'-endo -162° U13 G7 -177° C3'-endo    
 52°   -79° (BI)             -100° (BI)   51° 
    C2'-exo -163° G14 C6 -158° C3'-endo    
 52°   -85° (BI)             -74° (BI)   50° 
    C3'-endo -158° C15 G5 -161° C3'-endo    
 51°   -85° (BI)             -69° (BI)   67° 
    C3'-endo -156° U16 G4 -171° C3'-endo    
 65°   -80° (BI)             -93° (BI)   54° 
    C3'-endo -160° G17 C3 -157° C3'-endo    
 63°   -85° (BI)             -72° (BI)   58° 
    C3'-endo -154° C18 G2 -163° C3'-endo    
 63°   -104° (BI)             -75° (BI)   55° 
    C3'-endo -148° C19 G1 -173° C3'-endo    


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 Classification]   

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