Dear Dr. Lu,
I have a PDB entry from which I'd like to get groove parameters. However, it seemst that because the DNA chains are not completely connected during the find_pair routine, the analyze routine cannot calculate the parameters. I have run this PDB entry as a whole, and also extracting the DNA chains I'm interested (please find them both attached in this post).
# command
find_pair 4xrs_dna.pdb
2 # duplex
8 # number of base-pairs
1 1 # explicit bp numbering/hetero atoms
1 30 1 # 1 + ....>L:...2_:[.DT]T-**+-A[.DA]:..34_:M<.... 7.99 1.08 26.53 10.95 11.47
4 28 0 # 2 | ....>L:...5_:[.DA]A-**--T[.DT]:..32_:M<.... 5.43 0.84 27.23 10.31 8.48
5 26 9 # 3 x ....>L:...6_:[.DC]C-**--T[.DT]:..30_:M<.... 2.42 0.92 25.10 10.44 4.51
8 24 0 # 4 | ....>L:...9_:[.DG]G-----C[.DC]:..28_:M<.... 1.94 1.69 62.83 10.24 5.47
9 23 9 # 5 x ....>L:..10_:[.DA]A-----T[.DT]:..27_:M<.... 0.79 0.44 52.85 8.67 -0.69
12 20 1 # 6 + ....>L:..13_:[.DA]A-**+-T[.DT]:..24_:M<.... 1.12 0.86 61.41 8.40 4.90
14 18 0 # 7 | ....>L:..15_:[.DT]T-**+-A[.DA]:..22_:M<.... 3.48 0.53 63.53 9.27 7.71
15 16 0 # 8 | ....>L:..16_:[.DG]G-**+-T[.DT]:..17_:L<.... 7.51 1.27 52.73 6.84 11.70
##### Base-pair criteria used: 4.00 0.00 15.00 2.50 65.00 4.50 7.80 [ O N]
##### 6 non-Watson-Crick base-pairs, and 5 helices (2 isolated bps)
##### Helix #1 (1): 1
##### Helix #2 (2): 2 - 3 ***broken O3' to P[i+1] linkage***
##### Helix #3 (2): 4 - 5
##### Helix #4 (1): 6
##### Helix #5 (2): 7 - 8 ***broken O3' to P[i+1] linkage***Is the main reason for this structure not being completed the broken linkages? is it possible to fix the linkages with 3DNA or increase the distance threshold to tolerate them, in order to recover the al the base pairs and then calculate the grooves?
At the moment, the groove parameters are empty.
(output from analyze 4xrs_dna.inp. Only eight base pairs from the DNA-duplex are recovered and shown).
Minor and major groove widths: direct P-P distances and refined P-P distances
which take into account the directions of the sugar-phosphate backbones
(Subtract 5.8 Angstrom from the values to take account of the vdw radii
of the phosphate groups, and for comparison with FreeHelix and Curves.)
Ref: M. A. El Hassan and C. R. Calladine (1998). ``Two Distinct Modes of
Protein-induced Bending in DNA.'' J. Mol. Biol., v282, pp331-343.
Minor Groove Major Groove
P-P Refined P-P Refined
1 TA/TA --- --- --- ---
2 AC/TT --- --- --- ---
3 CG/CT --- --- --- ---
4 GA/TC --- --- --- ---
5 AA/TT --- --- --- ---
6 AT/AT --- --- --- ---
7 TG/TA --- --- --- ---Thank you for any feedback or suggestion,
Ignacio
P.S. This is a similar post that reports a similar warning.
http://forum.x3dna.org/general-discussions/this-structure-has-broken-o3'-to-p(i1)-linkages/