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Analysis of nucleic acid double helix geometry

Title CRYSTAL STRUCTURE OF CENP-B(1-129) COMPLEXED WITH THE CENP- B BOX DNA
PDB code 1HLV   (PDB summary)
NDB code PD0192 (NDB atlas)
Duplex length 21 base pairs
Protein Major Centromere Autoantigen B, DNA packing/chromatin, DNA binding domain: Alpha-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' G1 C2 C3 T4 T5 C6 G7 T8 T9 G10 G11 A12 A13 A14 C15 G16 G17 G18 A19 T20 T21 3'
Strand 2    3' C21 G20 G19 A18 A17 G16 C15 A14 A13 C12 C11 T10 T9 T8 G7 C6 C5 C4 T3 A2 A1 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      

G1 C21            
    3.3 -0.6 -0.2 34° -2°
C2 G20            
    3.2 1.0 -0.0 33°
C3 G19            
    3.3 -0.2 -0.3 29°
T4 A18            
    3.2 -0.5 -0.5 36°
T5 A17            
    3.5 0.3 0.1 44° -4°
C6 G16            
    3.5 0.8 0.4 39°
G7 C15            
    3.1 -0.6 -0.0 31° -2° -4°
T8 A14            
    3.3 1.3 0.1 36°
T9 A13            
    3.3 -1.3 0.3 43° -6° -10°
G10 C12            
    3.5 1.2 0.1 35° -6°
G11 C11            
    3.2 -1.3 0.3 37° -5°
A12 T10            
    3.3 0.6 -0.3 32° -2°
A13 T9            
    3.6 -0.1 -0.1 39° -2° -4°
A14 T8            
    3.3 -0.8 -1.0 30° -3°
C15 G7            
    3.3 0.3 1.0 34°
G16 C6            
    3.0 0.4 0.3 24° 11° -3°
G17 C5            
    3.6 -0.4 0.1 38° -3°
G18 C4            
    3.5 0.4 -0.3 38° -0° -3°
A19 T3            
    3.4 -0.2 -0.3 36°
T20 A2            
    3.2 -0.4 0.2 34°
T21 A1            


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 

    C2'-endo -119° G1 C21 -143° C2'-endo    
 48°   -75° (BI)             -105° (BI)   47° 
    C2'-endo -110° C2 G20 -118° C2'-endo    
 41°   -89° (BI)             -12° (BI)   40° 
    C2'-endo -104° C3 G19 -104° C2'-endo    
 47°   -67° (BI)             -88° (BI)   -64° 
    C1'-exo -119° T4 A18 -102° C3'-exo    
 47°   -56° (BI)             -58° (BI)   50° 
    C2'-endo -112° T5 A17 -103° C2'-endo    
 37°   -66° (BI)             -38° (BI)   47° 
    C2'-endo -97° C6 G16 -103° C2'-endo    
 41°   -68° (BI)             63° (BII)   46° 
    C2'-endo -95° G7 C15 -79° C2'-endo    
 46°   -36° (BI)             -58° (BI)   47° 
    C2'-endo -103° T8 A14 -99° C2'-endo    
 45°   -73° (BI)             36° (BII)   53° 
    C2'-endo -83° T9 A13 -94° C2'-endo    
 49°   108° (BII)             -85° (BI)   45° 
    C2'-endo -106° G10 C12 -116° C2'-endo    
 50°   -83° (BI)             74° (BII)   49° 
    C2'-endo -94° G11 C11 -103° C2'-endo    
 48°   53° (BII)             -51° (BI)   42° 
    C2'-endo -111° A12 T10 -104° C2'-endo    
 44°   -88° (BI)             -71° (BI)   48° 
    C2'-endo -98° A13 T9 -111° C2'-endo    
 35°   5° (BI)             -82° (BI)   -54° 
    O1'-endo -144° A14 T8 -102° C2'-endo    
 32°   -86° (BI)             -61° (BI)   52° 
    C1'-exo -134° C15 G7 -105° C2'-endo    
 51°   -52° (BI)             54° (BII)   34° 
    C2'-endo -97° G16 C6 -82° C2'-endo    
 37°   -48° (BI)             -46° (BI)   40° 
    C2'-endo -75° G17 C5 -114° C2'-endo    
 48°   96° (BII)             -72° (BI)   47° 
    C2'-endo -111° G18 C4 -118° C2'-endo    
 46°   -72° (BI)             -85° (BI)   -74° 
    C2'-endo -114° A19 T3 -118° C3'-exo    
 44°   -81° (BI)             -48° (BI)   57° 
    C2'-endo -113° T20 A2 -113° C2'-endo    
 56°   -36° (BI)             -80° (BI)   60° 
    C2'-endo -114° T21 A1 -107° C2'-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.


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