Thanks for your feedback, and for sharing your code with the community. Yes, JSON is the preferred means to connect 3DNA/DSSR to the outside world.
Best regards,
Xiang-Jun
PS. As a side note, DSSR also has the option --torsion-file (undocumented) which outputs commonly used backbone parameters, including pseudo-torsions you referred to. It serves as the replacement of "analyze -t", and may be useful for quick visual examinations of the output. Here is the DSSR command and output for PDB id 355d (the classic B-DNA dodecamer).
x3dna-dssr -i=355d.pdb --torsion-file -o=355d-tor.txt
Output of DNA/RNA backbone conformational parameters
DSSR v1.9.8-2019oct16 by xiangjun@x3dna.org
******************************************************************************************
Main chain conformational parameters:
alpha: O3'(i-1)-P-O5'-C5'
beta: P-O5'-C5'-C4'
gamma: O5'-C5'-C4'-C3'
delta: C5'-C4'-C3'-O3'
epsilon: C4'-C3'-O3'-P(i+1)
zeta: C3'-O3'-P(i+1)-O5'(i+1)
e-z: epsilon-zeta (BI/BII backbone classification)
chi for pyrimidines(Y): O4'-C1'-N1-C2; purines(R): O4'-C1'-N9-C4
Range [170, -50(310)] is assigned to anti, and [50, 90] to syn
phase-angle: the phase angle of pseudorotation and puckering
sugar-type: ~C2'-endo for C2'-endo like conformation, or
~C3'-endo for C3'-endo like conformation
Note the ONE column offset (for easy visual distinction)
ssZp: single-stranded Zp, defined as the z-coordinate of the 3' phosphorus atom
(P) expressed in the standard reference frame of the 5' base; the value is
POSITIVE when P lies on the +z-axis side (base in anti conformation);
NEGATIVE if P is on the -z-axis side (base in syn conformation)
Dp: perpendicular distance of the 3' P atom to the glycosidic bond
[Ref: Chen et al. (2010): "MolProbity: all-atom structure
validation for macromolecular crystallography."
Acta Crystallogr D Biol Crystallogr, 66(1):12-21]
splay: angle between the bridging P to the two base-origins of a dinucleotide.
nt alpha beta gamma delta epsilon zeta e-z chi phase-angle sugar-type ssZp Dp splay
1 C A.DC1 --- --- -70.0 144.7 -171.8 -98.4 -73(BI) -105.9(anti) 163.5(C2'-endo) ~C2'-endo 1.60 1.87 20.42
2 G A.DG2 -69.8 -172.2 43.0 148.1 -151.3 -157.0 6(..) -85.4(anti) 160.0(C2'-endo) ~C2'-endo 1.46 1.59 21.98
3 C A.DC3 -39.4 130.5 50.1 93.3 -165.4 -81.2 -84(BI) -132.4(anti) 65.3(C4'-exo) .... 2.36 3.05 17.11
4 G A.DG4 -64.8 174.4 50.1 145.0 -167.3 -144.6 -23(..) -93.7(anti) 156.2(C2'-endo) ~C2'-endo 2.19 2.01 20.93
5 A A.DA5 -47.1 156.2 53.7 133.0 -177.5 -90.7 -87(BI) -118.6(anti) 158.0(C2'-endo) ~C2'-endo 1.92 2.02 19.68
6 A A.DA6 -64.2 -173.0 46.3 128.0 176.9 -95.8 -87(BI) -109.2(anti) 152.6(C2'-endo) ~C2'-endo 1.87 2.02 18.84
7 T A.DT7 -49.0 172.9 48.6 112.7 -176.6 -95.6 -81(BI) -119.6(anti) 125.2(C1'-exo) ~C2'-endo 2.03 2.27 18.01
8 T A.DT8 -54.1 168.3 53.4 114.0 171.5 -95.0 -94(BI) -119.9(anti) 126.9(C1'-exo) ~C2'-endo 2.09 2.31 20.88
9 C A.DC9 -53.3 -173.2 50.8 138.3 -155.9 -96.3 -60(BI) -112.3(anti) 157.9(C2'-endo) ~C2'-endo 1.17 1.63 19.40
10 G A.DG10 -60.3 163.2 39.5 143.2 -100.0 146.3 114(BII) -83.6(anti) 145.6(C2'-endo) ~C2'-endo 1.41 1.25 21.62
11 C A.DC11 -73.1 144.3 50.8 143.5 -164.4 -126.1 -38(BI) -112.8(anti) 163.8(C2'-endo) ~C2'-endo 1.11 1.67 19.40
12 G A.DG12 52.9 144.1 -65.6 147.9 --- --- --- -79.3(anti) 207.4(C3'-exo) .... --- --- ---
1 C B.DC13 --- --- 58.5 138.1 -169.0 -104.8 -64(BI) -106.9(anti) 163.5(C2'-endo) ~C2'-endo 1.67 1.97 18.36
2 G B.DG14 -58.3 166.6 49.5 115.0 178.2 -94.3 -88(BI) -110.2(anti) 129.6(C1'-exo) ~C2'-endo 2.27 2.38 21.74
3 C B.DC15 -56.8 160.1 56.8 82.1 -174.4 -84.7 -90(BI) -137.2(anti) 42.0(C4'-exo) ~C3'-endo 3.17 3.82 18.25
4 G B.DG16 -61.6 175.5 62.1 140.9 150.8 -89.6 -120(BI) -101.7(anti) 168.8(C2'-endo) ~C2'-endo 2.20 2.01 22.29
5 A B.DA17 -56.3 -160.2 54.1 145.8 -178.3 -91.9 -86(BI) -108.3(anti) 173.3(C2'-endo) ~C2'-endo 1.36 1.79 18.87
6 A B.DA18 -61.5 175.7 45.3 113.1 166.4 -91.2 -102(BI) -112.4(anti) 127.5(C1'-exo) ~C2'-endo 2.20 2.33 18.64
7 T B.DT19 -49.1 178.5 51.6 127.6 -172.8 -106.8 -66(BI) -115.9(anti) 143.0(C1'-exo) ~C2'-endo 1.86 2.11 19.09
8 T B.DT20 -44.5 171.8 43.4 135.3 -164.1 -106.8 -57(BI) -110.1(anti) 151.4(C2'-endo) ~C2'-endo 1.45 1.84 19.32
9 C B.DC21 -58.1 159.5 51.3 95.5 -170.1 -81.3 -89(BI) -124.4(anti) 93.3(O4'-endo) .... 1.97 2.48 17.95
10 G B.DG22 -67.1 177.0 45.3 143.5 -148.6 -173.0 24(..) -86.2(anti) 151.2(C2'-endo) ~C2'-endo 1.96 1.90 23.90
11 C B.DC23 -57.2 129.7 51.4 83.8 -161.3 -77.6 -84(BI) -150.3(anti) 17.5(C3'-endo) ~C3'-endo 3.83 4.34 18.70
12 G B.DG24 -62.1 169.8 52.8 87.7 --- --- --- -141.3(anti) 13.7(C3'-endo) ~C3'-endo --- --- ---
******************************************************************************************
Virtual eta/theta torsion angles:
eta: C4'(i-1)-P(i)-C4'(i)-P(i+1)
theta: P(i)-C4'(i)-P(i+1)-C4'(i+1)
[Ref: Olson (1980): "Configurational statistics of polynucleotide chains.
An updated virtual bond model to treat effects of base stacking."
Macromolecules, 13(3):721-728]
eta': C1'(i-1)-P(i)-C1'(i)-P(i+1)
theta': P(i)-C1'(i)-P(i+1)-C1'(i+1)
[Ref: Keating et al. (2011): "A new way to see RNA." Quarterly Reviews
of Biophysics, 44(4):433-466]
eta": base(i-1)-P(i)-base(i)-P(i+1)
theta": P(i)-base(i)-P(i+1)-base(i+1)
nt eta theta eta' theta' eta" theta"
1 C A.DC1 --- --- --- --- --- ---
2 G A.DG2 165.5 -161.7 -165.6 -177.4 -126.7 -112.3
3 C A.DC3 179.5 -145.2 -171.9 -147.9 -105.8 -123.9
4 G A.DG4 158.9 -162.8 -164.8 -179.1 -135.8 -131.6
5 A A.DA5 174.5 -128.4 -163.1 -149.5 -114.7 -104.0
6 A A.DA6 168.1 -148.3 -165.5 -160.7 -112.5 -121.4
7 T A.DT7 179.3 -155.6 -162.3 -163.0 -119.1 -121.9
8 T A.DT8 172.1 -161.9 -165.4 -168.5 -120.3 -121.7
9 C A.DC9 -173.0 -123.0 -152.9 -132.0 -106.6 -93.2
10 G A.DG10 174.2 158.6 -153.5 154.1 -115.5 -152.3
11 C A.DC11 174.4 -105.9 -158.7 -137.8 -113.5 -106.3
12 G A.DG12 --- --- --- --- --- ---
1 C B.DC13 --- --- --- --- --- ---
2 G B.DG14 166.8 -152.9 -169.8 -166.3 -123.0 -106.1
3 C B.DC15 174.1 -170.1 -172.6 -164.6 -104.0 -144.2
4 G B.DG16 155.8 -134.3 -157.9 -167.2 -135.1 -111.4
5 A B.DA17 -177.5 -121.1 -153.7 -142.5 -94.4 -102.8
6 A B.DA18 164.2 -162.9 -170.6 -170.2 -122.5 -128.1
7 T B.DT19 -178.9 -149.1 -158.1 -158.7 -114.1 -116.5
8 T B.DT20 177.8 -138.9 -158.3 -153.9 -113.9 -104.5
9 C B.DC21 173.0 -152.9 -171.8 -151.0 -118.0 -122.5
10 G B.DG22 163.1 173.9 -167.2 156.7 -137.5 -141.3
11 C B.DC23 167.8 -144.6 169.4 -150.8 -124.1 -124.9
12 G B.DG24 --- --- --- --- --- ---
******************************************************************************************
Sugar conformational parameters:
v0: C4'-O4'-C1'-C2'
v1: O4'-C1'-C2'-C3'
v2: C1'-C2'-C3'-C4'
v3: C2'-C3'-C4'-O4'
v4: C3'-C4'-O4'-C1'
tm: the amplitude of pucker
P: the phase angle of pseudorotation
[Ref: Altona & Sundaralingam (1972): "Conformational analysis
of the sugar ring in nucleosides and nucleotides. A new
description using the concept of pseudorotation."
J Am Chem Soc, 94(23):8205-8212]
nt v0 v1 v2 v3 v4 tm P Puckering
1 C A.DC1 -20.3 33.1 -33.1 22.1 -1.2 34.5 163.5 C2'-endo
2 G A.DG2 -23.9 36.6 -34.9 22.3 0.8 37.1 160.0 C2'-endo
3 C A.DC3 -24.8 5.6 13.9 -28.7 33.8 33.3 65.3 C4'-exo
4 G A.DG4 -25.7 37.1 -33.9 20.1 3.4 37.1 156.2 C2'-endo
5 A A.DA5 -20.9 31.2 -29.3 17.7 2.0 31.6 158.0 C2'-endo
6 A A.DA6 -22.6 30.8 -27.2 14.8 4.8 30.6 152.6 C2'-endo
7 T A.DT7 -34.2 33.1 -20.1 0.8 20.9 34.8 125.2 C1'-exo
8 T A.DT8 -35.8 35.4 -22.0 1.8 21.1 36.7 126.9 C1'-exo
9 C A.DC9 -21.5 31.7 -29.8 18.0 2.0 32.2 157.9 C2'-endo
10 G A.DG10 -36.1 45.1 -36.0 16.8 11.4 43.6 145.6 C2'-endo
11 C A.DC11 -21.3 35.1 -35.2 23.4 -1.5 36.6 163.8 C2'-endo
12 G A.DG12 4.1 12.3 -22.5 25.4 -18.8 25.4 207.4 C3'-exo
1 C B.DC13 -18.0 29.3 -29.4 19.4 -1.0 30.7 163.5 C2'-endo
2 G B.DG14 -31.7 32.2 -21.1 3.2 17.9 33.1 129.6 C1'-exo
3 C B.DC15 -15.4 -9.0 28.1 -37.8 33.6 37.8 42.0 C4'-exo
4 G B.DG16 -15.6 28.7 -30.2 21.8 -4.0 30.8 168.8 C2'-endo
5 A B.DA17 -13.5 27.8 -31.1 23.6 -6.5 31.4 173.3 C2'-endo
6 A B.DA18 -31.3 31.1 -19.7 1.9 18.6 32.4 127.5 C1'-exo
7 T B.DT19 -28.9 34.5 -27.4 11.1 11.1 34.2 143.0 C1'-exo
8 T B.DT20 -28.0 37.2 -32.5 17.2 6.6 37.1 151.4 C2'-endo
9 C B.DC21 -40.0 25.4 -2.4 -21.1 38.2 40.6 93.3 O4'-endo
10 G B.DG22 -30.7 41.1 -35.3 19.0 6.9 40.3 151.2 C2'-endo
11 C B.DC23 0.6 -22.5 34.5 -35.1 21.6 36.2 17.5 C3'-endo
12 G B.DG24 2.9 -23.2 33.3 -32.7 18.6 34.3 13.7 C3'-endo
******************************************************************************************
Assignment of sugar-phosphate backbone suites
bin: name of the 12 bins based on [delta(i-1), delta, gamma], where
delta(i-1) and delta can be either 3 (for C3'-endo sugar) or 2
(for C2'-endo) and gamma can be p/t/m (for gauche+/trans/gauche-
conformations, respectively) (2x2x3=12 combinations: 33p, 33t,
... 22m); 'inc' refers to incomplete cases (i.e., with missing
torsions), and 'trig' to triages (i.e., with torsion angle
outliers)
cluster: 2-char suite name, for one of 53 reported clusters (46
certain and 7 wannabes), '__' for incomplete cases, and
'!!' for outliers
suiteness: measure of conformer-match quality (low to high in range 0 to 1)
[Ref: Richardson et al. (2008): "RNA backbone: consensus all-angle
conformers and modular string nomenclature (an RNA Ontology
Consortium contribution)." RNA, 14(3):465-481]
nt bin cluster suiteness
1 C A.DC1 inc __ 0
2 G A.DG2 22p !! 0
3 C A.DC3 23p !! 0
4 G A.DG4 32p 1b 0.573
5 A A.DA5 22p !! 0
6 A A.DA6 22p !! 0
7 T A.DT7 trig !! 0
8 T A.DT8 trig !! 0
9 C A.DC9 trig !! 0
10 G A.DG10 22p !! 0
11 C A.DC11 22p 4b 0.533
12 G A.DG12 22m !! 0
1 C B.DC13 inc __ 0
2 G B.DG14 trig !! 0
3 C B.DC15 trig !! 0
4 G B.DG16 32p 1b 0.476
5 A B.DA17 trig !! 0
6 A B.DA18 trig !! 0
7 T B.DT19 trig !! 0
8 T B.DT20 22p !! 0
9 C B.DC21 23p !! 0
10 G B.DG22 32p 1b 0.369
11 C B.DC23 23p 0a 0.015
12 G B.DG24 33p 1a 0.790
Concatenated suite string per chain. To avoid confusion of lower case
modified nucleotide name (e.g., 'a') with suite cluster (e.g., '1a'),
use --suite-delimiter to add delimiters (matched '()' by default).
1 A DNA nts=12 C!!G!!C1bG!!A!!A!!T!!T!!C!!G4bC!!G
2 B DNA nts=12 C!!G!!C1bG!!A!!A!!T!!T!!C1bG0aC1aG