Hi Honglue,
The info is already there, as shown below for 355d.
x3dna-dssr -i=355d.pdb --json | jq .stems
You will see the following at the top:
[
{
"index": 1,
"helix_index": 1,
"strand1": "CGCGAATTCGCG",
"strand2": "GCGCTTAAGCGC",
"bp_type": "||||||||||||",
"helix_form": "BBBBBBBBBBB",
"num_pairs": 12,
"pairs": [
{
"index": 1,
"nt1": "A.DC1",
"nt2": "B.DG24",
"bp": "C-G",
"name": "WC",
"Saenger": "19-XIX",
"LW": "cWW",
"DSSR": "cW-W"
},
....
]
Xiang-Jun