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 PURINE REPRESSOR MUTANT-HYPOXANTHINE-PURF OPERATOR COMPLEX
PDB code 1JH9   (PDB summary)
NDB code PD0226 (NDB atlas)
Duplex length 16 base pairs
Protein Purine Repressor, Transcription Factor, DNA binding domain: Alpha-helix, DNA binding domain: Helix-turn-helix

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' A700 C701 G702 A703 A704 A705 A706 C707 G708 T709 T710 T711 T712 C713 G714 T715 3'
Strand 2    3' T715 G714 C713 T712 T711 T710 T709 G708 C707 A706 A705 A704 A703 G702 C701 A700 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      

A700 T715            
    3.5 0.4 -0.3 33° -0°
C701 G714            
    3.3 -0.6 -0.5 38° -6°
G702 C713            
    3.5 -0.4 0.1 32° -3°
A703 T712            
    3.2 1.2 0.2 32° -3°
A704 T711            
    3.2 -0.3 0.2 43° -7° -4°
A705 T710            
    3.3 0.7 -0.6 37° -6°
A706 T709            
    3.1 -1.3 -0.8 21° -4°
C707 G708            
    5.5 0.0 0.8 31° 47°
G708 C707            
    3.1 1.3 -0.8 21° -4° -6°
T709 A706            
    3.3 -0.7 -0.6 37°
T710 A705            
    3.2 0.3 0.2 43° -7°
T711 A704            
    3.2 -1.2 0.2 32° -3° -0°
T712 A703            
    3.5 0.4 0.1 32° -3° -6°
C713 G702            
    3.3 0.6 -0.5 38° -6° -4°
G714 C701            
    3.5 -0.4 -0.3 33°
T715 A700            


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 

    C4'-exo -114° A700 T715 -127° C2'-endo    
 146°   -153° (BI)             -105° (BI)   -162° 
    O1'-endo -164° C701 G714 -162° C3'-endo    
 75°   -81° (BI)             -98° (BI)   -116° 
    C2'-endo -131° G702 C713 -144° C3'-exo    
 4°   -40° (BI)             -41° (BI)   29° 
    C3'-exo -88° A703 T712 -96° C2'-endo    
 46°   -93° (BI)             24° (BII)   55° 
    C2'-endo -80° A704 T711 -94° C2'-endo    
 11°   90° (BII)             -66° (BI)   43° 
    C3'-exo -91° A705 T710 -98° C3'-exo    
 52°   -73° (BI)             -93° (BI)   -161° 
    O1'-endo -123° A706 T709 -170° C4'-exo    
 34°   -38° (BI)             -30° (BI)   14° 
    C4'-exo -115° C707 G708 -82° C2'-endo    
 14°   -41° (BI)             -41° (BI)   34° 
    C2'-endo -82° G708 C707 -115° C4'-exo    
 -161°   -30° (BI)             -38° (BI)   52° 
    C4'-exo -170° T709 A706 -123° O1'-endo    
 43°   -93° (BI)             -73° (BI)   11° 
    C3'-exo -98° T710 A705 -91° C3'-exo    
 55°   -66° (BI)             90° (BII)   46° 
    C2'-endo -94° T711 A704 -80° C2'-endo    
 29°   24° (BII)             -93° (BI)   4° 
    C2'-endo -96° T712 A703 -88° C3'-exo    
 -116°   -41° (BI)             -40° (BI)   75° 
    C3'-exo -144° C713 G702 -131° C2'-endo    
 -162°   -98° (BI)             -81° (BI)   146° 
    C3'-endo -162° G714 C701 -164° O1'-endo    
 81°   -105° (BI)             -153° (BI)   77° 
    C2'-endo -127° T715 A700 -114° 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