By following citations to 3DNA/DSSR, I recently came across the paper "RNAtango: Analysing and comparing RNA 3D structures via torsional angles" in PLOS Computational Biology by Mackowiak M, Adamczyk B, Szachniuk M, and Zok T. This work provides a nice summary of definitions of torsion and pseudo-torsion angles in RNA structure, and an angular metrics (MCQ, Mean of Circular Quantities) to score structure similarity. The RNAtango web application allows user to explore the distribution of torsion angles in a single structure/fragment (Single model), compare RNA models with a native structure (Models vs Target), or perform a comparative analysis in a set of models (Model vs Model).
In the Introduction section, 3DNA/DSSR are mentioned along with other related tools, as below:
Several bioinformatics tools have been designed for analyzing torsion and pseudotorsion angles, each with its own strengths and limitations. 3DNA, an open-source toolkit, provides comprehensive functionality, including torsion and pseudotorsion angle calculations [27], but lacks support for the current standard PDBx/mmCIF file format. DSSR, the successor to 3DNA, overcomes this limitation by supporting both PDB and PDBx/mmCIF files. However, it is a closed-source, commercial application that requires licensing, even for research purposes [28]. Curves+, another tool used for torsion angle analysis, is currently inaccessible due to the unavailability of its webpage and source code hosting [29]. Barnaba, a Python library and toolset for analyzing single structures or trajectories, supports torsion angle calculations but, like 3DNA, does not support the PDBx/mmCIF format [30]. For users seeking a more user friendly option, AMIGOS III offers a PyMOL plugin that calculates pseudotorsion angles and presents them in Ramachandran-like plots [17].
Every bioinformatic software has been developed for a specific purpose, and no two such tools can be identical. It is a good thing that the community has a choice for RNA backbone analysis. Indeed, 3DNA has been superseded by DSSR, which is licensed by Columbia Technology Ventures (CTV) to ensure its continuous development and availability. However, DSSR remain competitive due to its unmatched functionality, usability, and support: it saves users a substantial amount of time and effort when compared to other options.
From the very beginning, it has been my dream to make DSSR stand out for its quality and value, and be widely accessible. The CTV DSSR distribution by no means follow typical commercial license for a software product: specifically, it does not include a license key to limit DSSR's usage to a specific machine and operating system, and there is no expire date for the software either. Moreover, the Basic Academic license was free of charge when DSSR was initially licensed by the CTV in August 2020, and remained so until around end of 2021 when the web-based "Express Licenses" functionality no longer worked. Manually handling the large number of requests for free academic licenses was not sustainable, and that was when the DSSR Basic Academic free license was removed. Upon user requests, we late on re-introduced DSSR Basic Academic license, but with a one-time fee of $200 to cover the running cost. That may be reason for the remark in the RNAtango paper that DSSR "requires licensing, even for research purposes".
With the recent NIH R24 funding support on "X3DNA-DSSR: a resource for structural bioinformatics of nucleic acids", we are providing DSSR Basic free of charge to the academic community. Academic Users may submit a license request for DSSR Basic or DSSR Pro by clicking "Express Licensing". Checking the list of licensees, I am thrilled to see the many new DSSR users from leading institutions around the world, including Stockholm University, Ghent University, Universitaet Heidelberg, University of Palermo, CSSB-Hamburg, Nicolaus Copernicus University, NIH, Harvard, ... Clearly, DSSR fills a niche, and the demands for it remain strong!
Back to torsion angles, it is safe to say that DSSR has unique features not available or easily accessible elsewhere. Here are some use cases using tRNA PDB entry 1ehz as an example:
x3dna-dssr -i=1ehz.cif # generate dssr-torsions.txt among other output files
x3dna-dssr -i=1ehz.cif --torsion-file -o=1ehz-torsions.txt # just the torsion file 1ehz-torsions.txt
x3dna-dssr -i=1ehz.cif --json | jq .nts[54] > 1ehz-PSU55.txt # DSSR-derived features for nucleotide PSU55Users can easily run the DSSR commands listed above and get the results in human-readable text and machine-friendly JSON formats. For verification, the contents of 1ehz-torsions.txt and 1ehz-PSU55.txt are available by clicking the links.
It is worth noting that DSSR has the --nmr option for the analysis of an ensemble of NMR structures, in .pdb or .cif format, as deposited in the PDB. The combination of --nmr and --json renders DSSR easily accessible to the molecular dynamics (MD) community.
In principle, calculating torsion angles is a straightforward process. In reality, factors such as modified nucleotides (especially pseudouridine), missing atoms, NMR ensembles or MD trajectories, PDB vs mmCIF formats, etc. make the implementation complicated. Without paying great attention to details, it is easy to make subtle mistakes. For example, with RNAtango the chi (χ) torsion angle for A.PSU55 of 1ehz is listed as -152.42°, which is wrong. The correct value should be -147.0° as reported by DSSR (see below and the link 1ehz-PSU55.txt above).
DSSR provides a comprehensive list of backbone parameters (as listed below for 1ehz). The program is efficient and robust, and has been battle tested. I am always quick to fix any bugs once verified, and am willing to add new features once thoroughly studied. In short, DSSR has been designed to be a reliable tool that the community can trust and build upon.
DSSR-derived backbone features for tRNA 1ehz:
Output of DNA/RNA backbone conformational parameters
DSSR v2.4.5-2024sep24 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 G A.G1 --- -128.1 67.8 82.9 -155.6 -68.6 -87(BI) -167.8(anti) 16.1(C3'-endo) ~C3'-endo 4.59 4.57 24.92
2 C A.C2 -67.4 -178.4 53.8 83.4 -145.1 -76.8 -68(BI) -163.8(anti) 16.1(C3'-endo) ~C3'-endo 4.52 4.63 21.15
3 G A.G3 -74.5 169.7 59.5 80.7 -148.3 -80.0 -68(BI) -161.9(anti) 14.6(C3'-endo) ~C3'-endo 4.75 4.69 22.28
4 G A.G4 -64.4 162.2 60.7 82.2 -157.4 -68.7 -89(BI) -168.7(anti) 20.8(C3'-endo) ~C3'-endo 4.68 4.57 25.22
5 A A.A5 -74.7 -176.5 53.4 84.9 -137.5 -81.7 -56(BI) -162.9(anti) 4.8(C3'-endo) ~C3'-endo 4.49 4.76 22.04
6 U A.U6 -48.8 157.6 55.3 81.3 -151.0 -77.0 -74(BI) -160.0(anti) 18.2(C3'-endo) ~C3'-endo 4.31 4.51 22.89
7 U A.U7 -59.5 -178.7 62.5 137.3 -105.9 -52.0 -54(--) -133.1(anti) 156.1(C2'-endo) ~C2'-endo 1.55 1.41 126.99
8 U A.U8 -83.8 -145.6 55.4 78.6 -142.8 -118.6 -24(--) -161.5(anti) 10.5(C3'-endo) ~C3'-endo 4.60 4.76 62.37
9 A A.A9 -69.7 -141.7 52.3 147.8 -106.2 -77.3 -29(--) -70.5(anti) 149.8(C2'-endo) ~C2'-endo 1.00 1.14 57.38
10 g A.2MG10 177.8 147.2 60.1 89.3 -126.2 -88.7 -37(--) 169.6(anti) 6.6(C3'-endo) ~C3'-endo 4.68 4.63 23.87
11 C A.C11 -56.1 167.9 48.2 87.2 -150.5 -69.9 -81(BI) -160.9(anti) 16.8(C3'-endo) ~C3'-endo 4.28 4.46 21.20
12 U A.U12 -67.8 172.9 51.8 80.7 -158.5 -65.2 -93(BI) -158.3(anti) 25.2(C3'-endo) ~C3'-endo 4.29 4.45 21.01
13 C A.C13 166.6 -169.9 178.6 82.5 -153.1 -97.4 -56(BI) -168.3(anti) 23.7(C3'-endo) ~C3'-endo 4.28 4.36 31.59
14 A A.A14 83.4 -158.3 -114.6 92.0 -125.5 -57.3 -68(--) -170.7(anti) 358.9(C2'-exo) ~C3'-endo 4.67 4.74 38.01
15 G A.G15 -55.1 162.5 51.9 79.8 -136.3 -143.9 8(--) -164.5(anti) 16.0(C3'-endo) ~C3'-endo 4.72 4.74 26.17
16 u A.H2U16 -6.1 91.2 76.8 96.8 -61.8 -131.2 69(--) -85.8(anti) 18.8(C3'-endo) ~C3'-endo -0.71 3.38 145.77
17 u A.H2U17 27.8 107.7 174.1 94.8 178.0 76.2 102(--) -142.5(anti) 341.4(C2'-exo) ~C3'-endo -0.90 4.20 105.55
18 G A.G18 45.4 -159.4 59.0 150.6 -95.2 -179.1 84(BII) -99.5(anti) 154.3(C2'-endo) ~C2'-endo 1.60 1.09 51.64
19 G A.G19 -71.4 -178.9 53.8 153.8 -91.6 -83.7 -8(--) -80.3(anti) 167.6(C2'-endo) ~C2'-endo -1.14 0.48 130.30
20 G A.G20 -81.3 -150.7 47.8 89.9 -122.3 -54.1 -68(--) 177.8(anti) 8.7(C3'-endo) ~C3'-endo 4.90 4.76 57.04
21 A A.A21 -75.6 148.6 -176.6 78.2 -168.9 -75.6 -93(BI) -160.2(anti) 13.0(C3'-endo) ~C3'-endo 4.00 4.26 40.66
22 G A.G22 158.8 153.5 179.3 82.0 -145.0 -80.4 -65(BI) -175.5(anti) 353.8(C2'-exo) ~C3'-endo 4.60 4.73 25.62
23 A A.A23 -53.3 174.8 52.5 82.3 -155.3 -66.4 -89(BI) -158.0(anti) 12.6(C3'-endo) ~C3'-endo 4.18 4.61 22.96
24 G A.G24 -68.8 178.2 46.8 83.6 -144.3 -72.8 -71(BI) -160.7(anti) 13.4(C3'-endo) ~C3'-endo 4.63 4.74 20.51
25 C A.C25 -65.1 168.9 53.9 83.3 -145.1 -68.4 -77(BI) -160.3(anti) 17.4(C3'-endo) ~C3'-endo 4.56 4.70 30.70
26 g A.M2G26 -53.8 170.8 47.7 86.0 -136.3 -76.9 -59(BI) -163.4(anti) 9.3(C3'-endo) ~C3'-endo 4.57 4.67 27.36
27 C A.C27 -53.0 166.9 43.6 83.4 -148.5 -73.4 -75(BI) -168.2(anti) 18.3(C3'-endo) ~C3'-endo 4.53 4.62 23.07
28 C A.C28 -72.4 178.3 49.3 80.1 -152.1 -67.0 -85(BI) -160.6(anti) 9.2(C3'-endo) ~C3'-endo 4.55 4.73 21.61
29 A A.A29 -66.6 174.0 55.6 81.4 -155.5 -78.3 -77(BI) -165.9(anti) 13.7(C3'-endo) ~C3'-endo 4.73 4.65 26.96
30 G A.G30 -54.0 165.9 56.9 83.6 -144.7 -62.3 -82(BI) -171.7(anti) 14.5(C3'-endo) ~C3'-endo 4.67 4.65 25.72
31 A A.A31 -69.9 177.8 52.3 83.7 -137.0 -75.5 -61(BI) -156.7(anti) 14.6(C3'-endo) ~C3'-endo 4.24 4.72 21.52
32 c A.OMC32 -52.7 161.4 49.3 80.1 -145.9 -71.2 -75(BI) -149.9(anti) 20.4(C3'-endo) ~C3'-endo 4.16 4.63 25.94
33 U A.U33 -67.7 -177.0 47.0 82.1 -148.0 -53.7 -94(BI) -148.2(anti) 13.3(C3'-endo) ~C3'-endo 4.19 4.64 75.47
34 g A.OMG34 171.1 148.1 52.5 83.4 -132.5 -71.8 -61(BI) -171.2(anti) 12.2(C3'-endo) ~C3'-endo 4.15 4.58 22.09
35 A A.A35 -47.7 163.7 40.2 80.9 -143.7 -59.5 -84(BI) -154.4(anti) 21.9(C3'-endo) ~C3'-endo 4.20 4.54 20.57
36 A A.A36 -52.4 165.7 51.3 72.2 -160.4 -85.2 -75(BI) -158.4(anti) 45.8(C4'-exo) ~C3'-endo 4.49 4.31 24.48
37 g A.YYG37 -57.5 163.0 47.8 81.1 -148.1 -67.0 -81(BI) -168.8(anti) 15.4(C3'-endo) ~C3'-endo 4.63 4.65 32.08
38 A A.A38 -61.8 -180.0 46.9 82.5 -136.8 -76.4 -60(BI) -169.4(anti) 2.4(C3'-endo) ~C3'-endo 4.63 4.78 23.75
39 P A.PSU39 -47.7 160.4 53.3 79.3 -140.1 -68.6 -72(BI) -165.6(anti) 15.8(C3'-endo) ~C3'-endo 4.55 4.68 26.68
40 c A.5MC40 -67.4 172.0 56.2 83.2 -154.2 -74.9 -79(BI) -162.6(anti) 17.3(C3'-endo) ~C3'-endo 4.52 4.60 27.71
41 U A.U41 -68.2 -179.4 52.4 78.9 -137.3 -84.7 -53(BI) -169.0(anti) 13.4(C3'-endo) ~C3'-endo 4.54 4.75 24.14
42 G A.G42 -47.9 158.7 55.6 79.8 -160.3 -70.3 -90(BI) -169.0(anti) 20.9(C3'-endo) ~C3'-endo 4.43 4.51 23.54
43 G A.G43 -67.0 -178.3 55.6 81.6 -154.9 -76.4 -78(BI) -160.2(anti) 12.6(C3'-endo) ~C3'-endo 4.24 4.61 20.95
44 A A.A44 -59.7 162.1 60.0 85.3 -142.8 -57.2 -86(BI) -159.4(anti) 16.9(C3'-endo) ~C3'-endo 4.25 4.61 31.07
45 G A.G45 -71.9 -176.9 51.0 87.6 -135.1 -78.7 -56(BI) -149.3(anti) 15.4(C3'-endo) ~C3'-endo 4.01 4.58 40.27
46 g A.7MG46 -56.8 -146.5 48.4 141.6 -102.7 -137.9 35(--) -65.8(anti) 154.5(C2'-endo) ~C2'-endo 0.21 0.96 139.04
47 U A.U47 62.4 -164.0 44.4 146.1 -93.7 -78.0 -16(--) -112.0(anti) 164.9(C2'-endo) ~C2'-endo 0.26 0.39 157.37
48 C A.C48 -73.5 -174.3 161.5 145.6 -143.5 75.6 141(--) -140.1(anti) 158.2(C2'-endo) ~C2'-endo 1.92 1.80 147.54
49 c A.5MC49 50.7 168.5 42.2 84.3 -145.0 -82.1 -63(BI) -173.6(anti) 10.1(C3'-endo) ~C3'-endo 4.77 4.75 25.83
50 U A.U50 -51.7 177.2 42.1 80.4 -150.6 -67.8 -83(BI) -165.3(anti) 5.6(C3'-endo) ~C3'-endo 4.38 4.75 23.15
51 G A.G51 -63.9 176.8 52.8 79.4 -150.4 -71.3 -79(BI) -156.6(anti) 11.5(C3'-endo) ~C3'-endo 4.44 4.67 21.28
52 U A.U52 -64.7 173.6 48.5 80.3 -156.5 -69.4 -87(BI) -164.0(anti) 14.1(C3'-endo) ~C3'-endo 4.64 4.74 25.47
53 G A.G53 -56.9 171.5 56.2 83.9 -159.4 -64.9 -95(BI) -169.2(anti) 19.8(C3'-endo) ~C3'-endo 4.59 4.57 24.53
54 t A.5MU54 -79.7 -172.8 57.7 77.6 -128.6 -70.7 -58(BI) -161.5(anti) 20.6(C3'-endo) ~C3'-endo 4.56 4.80 30.73
55 P A.PSU55 -49.7 168.8 44.1 76.6 -140.8 -69.9 -71(BI) -147.0(anti) 10.1(C3'-endo) ~C3'-endo 4.15 4.74 71.28
56 C A.C56 166.4 171.8 53.3 83.4 -132.7 -70.6 -62(BI) -161.5(anti) 12.6(C3'-endo) ~C3'-endo 4.37 4.76 28.07
57 G A.G57 -65.7 167.1 57.5 81.7 -145.2 -67.6 -78(BI) -159.3(anti) 12.8(C3'-endo) ~C3'-endo 4.36 4.65 42.47
58 a A.1MA58 -60.8 -146.1 71.8 156.7 -78.3 -169.3 91(BII) -86.3(anti) 161.1(C2'-endo) ~C2'-endo 0.48 0.68 73.92
59 U A.U59 72.6 -158.8 63.7 84.6 -148.8 -53.7 -95(BI) -165.6(anti) 25.8(C3'-endo) ~C3'-endo 4.67 4.42 27.88
60 C A.C60 -72.2 179.5 66.0 148.3 -97.1 -66.4 -31(--) -117.8(anti) 154.8(C2'-endo) ~C2'-endo 0.99 0.86 90.64
61 C A.C61 -84.3 179.8 38.2 83.0 -152.3 -74.5 -78(BI) -166.7(anti) 14.8(C3'-endo) ~C3'-endo 4.45 4.52 25.80
62 A A.A62 -60.1 179.6 46.9 80.5 -145.6 -74.1 -71(BI) -158.7(anti) 9.9(C3'-endo) ~C3'-endo 4.18 4.66 19.23
63 C A.C63 -62.0 167.3 50.9 80.7 -152.3 -70.7 -82(BI) -152.6(anti) 10.7(C3'-endo) ~C3'-endo 4.32 4.62 23.62
64 A A.A64 -66.9 180.0 44.1 75.8 -147.5 -76.5 -71(BI) -161.8(anti) 12.9(C3'-endo) ~C3'-endo 4.68 4.86 25.64
65 G A.G65 -44.0 164.2 49.9 79.8 -152.0 -73.3 -79(BI) -172.8(anti) 16.5(C3'-endo) ~C3'-endo 4.92 4.76 25.20
66 A A.A66 -57.9 178.5 52.0 81.7 -151.0 -73.5 -77(BI) -164.9(anti) 22.5(C3'-endo) ~C3'-endo 4.56 4.60 22.73
67 A A.A67 -62.0 164.1 54.2 83.2 -152.2 -78.3 -74(BI) -162.8(anti) 15.0(C3'-endo) ~C3'-endo 4.71 4.67 23.30
68 U A.U68 -59.8 175.3 47.3 82.2 -152.9 -65.4 -88(BI) -160.1(anti) 11.2(C3'-endo) ~C3'-endo 4.30 4.60 24.35
69 U A.U69 -63.8 168.1 55.1 79.1 -155.4 -85.6 -70(BI) -161.4(anti) 14.7(C3'-endo) ~C3'-endo 4.55 4.61 19.23
70 C A.C70 -61.7 164.6 53.1 79.0 -158.5 -64.5 -94(BI) -152.0(anti) 15.0(C3'-endo) ~C3'-endo 4.20 4.56 20.96
71 G A.G71 -78.4 173.6 60.3 80.3 -149.6 -68.4 -81(BI) -162.8(anti) 13.5(C3'-endo) ~C3'-endo 4.50 4.71 22.80
72 C A.C72 -73.2 176.2 62.1 83.0 -152.3 -67.9 -84(BI) -161.6(anti) 19.5(C3'-endo) ~C3'-endo 4.56 4.63 26.14
73 A A.A73 -63.3 177.7 50.4 81.6 -148.2 -66.1 -82(BI) -167.4(anti) 15.0(C3'-endo) ~C3'-endo 4.65 4.71 26.33
74 C A.C74 -66.9 -174.9 50.7 85.9 -145.0 -58.8 -86(BI) -153.1(anti) 11.8(C3'-endo) ~C3'-endo 4.22 4.61 33.45
75 C A.C75 -52.3 175.7 42.3 85.6 -131.9 163.9 64(BII) -151.7(anti) 15.1(C3'-endo) ~C3'-endo 3.96 4.60 159.78
76 A A.A76 -71.0 130.2 164.6 160.9 --- --- --- 138.5(anti) 176.1(C2'-endo) ~C2'-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 G A.G1 --- -139.3 --- -136.5 --- -110.8
2 C A.C2 171.9 -144.6 -175.5 -144.1 -136.1 -118.1
3 G A.G3 160.2 -151.4 173.9 -153.9 -145.0 -143.7
4 G A.G4 164.3 -144.6 177.7 -144.1 -154.8 -98.7
5 A A.A5 166.9 -138.1 -178.3 -135.8 -116.3 -111.6
6 U A.U6 172.1 -149.7 -170.8 -143.9 -130.1 -126.5
7 U A.U7 -158.0 -42.7 -138.7 -60.7 -120.5 -31.5
8 U A.U8 162.7 160.7 -159.9 -163.8 -142.6 176.2
9 A A.A9 -140.6 -38.9 -159.3 -112.7 157.1 -105.5
10 g A.2MG10 27.8 -130.3 97.2 -130.1 134.8 -110.3
11 C A.C11 170.3 -135.8 -175.7 -136.7 -137.8 -119.9
12 U A.U12 159.9 -121.6 176.5 -130.6 -148.5 -101.4
13 C A.C13 178.1 -179.1 -166.8 176.7 -118.5 178.4
14 A A.A14 171.9 -146.5 172.1 -133.4 -179.7 -74.6
15 G A.G15 164.3 -177.9 -166.6 -161.0 -92.6 -101.8
16 u A.H2U16 -124.1 -77.5 -114.2 -108.3 -72.5 -127.0
17 u A.H2U17 -10.5 -64.3 7.7 -94.7 17.3 -125.4
18 G A.G18 -21.0 -167.4 45.3 -160.9 61.3 -124.2
19 G A.G19 -127.4 -43.3 -122.0 -72.9 -105.8 -7.8
20 G A.G20 165.3 -100.4 -160.4 -101.1 -177.9 -115.4
21 A A.A21 -78.3 152.7 -68.0 155.1 -61.1 154.8
22 G A.G22 159.5 167.6 156.6 178.8 157.1 -162.6
23 A A.A23 178.4 -141.8 -173.5 -141.2 -156.1 -112.0
24 G A.G24 163.7 -139.5 177.7 -137.6 -137.6 -103.8
25 C A.C25 161.4 -132.6 179.2 -131.0 -128.2 -89.0
26 g A.M2G26 173.0 -133.0 -167.7 -130.4 -106.9 -93.6
27 C A.C27 163.5 -142.3 -178.0 -141.5 -123.6 -105.6
28 C A.C28 157.5 -143.8 171.1 -144.3 -136.3 -125.5
29 A A.A29 163.5 -152.9 179.0 -150.8 -142.9 -124.7
30 G A.G30 178.3 -127.8 -167.7 -126.5 -128.2 -72.5
31 A A.A31 165.4 -133.9 -174.3 -131.0 -101.0 -93.9
32 c A.OMC32 164.5 -139.2 -175.9 -138.0 -122.3 -108.9
33 U A.U33 165.1 -114.0 177.8 -158.5 -141.1 138.3
34 g A.OMG34 27.3 -121.7 50.5 -123.7 22.7 -84.4
35 A A.A35 162.5 -127.7 -177.7 -128.5 -116.8 -113.4
36 A A.A36 164.9 -172.7 -174.4 -169.2 -142.3 -115.1
37 g A.YYG37 163.1 -135.2 174.1 -131.3 -119.8 -79.8
38 A A.A38 170.2 -133.9 -173.3 -129.0 -104.3 -105.5
39 P A.PSU39 174.0 -132.6 -168.6 -131.2 -127.5 -89.6
40 c A.5MC40 163.1 -148.5 -177.6 -149.3 -115.9 -131.7
41 U A.U41 169.4 -148.8 177.2 -144.0 -152.9 -120.5
42 G A.G42 171.2 -150.4 -171.5 -151.6 -133.9 -124.5
43 G A.G43 174.2 -151.6 -174.4 -150.0 -134.0 -124.5
44 A A.A44 173.2 -120.4 -171.8 -120.0 -133.3 -72.6
45 G A.G45 168.6 -141.6 -168.3 -128.4 -103.4 -133.4
46 g A.7MG46 -143.2 -107.3 -133.6 -149.6 -148.2 -162.7
47 U A.U47 -31.5 -56.8 4.8 -91.0 24.9 -110.7
48 C A.C48 -82.5 53.9 -29.3 17.5 1.5 -107.6
49 c A.5MC49 -56.7 -145.3 -36.6 -142.8 103.2 -130.2
50 U A.U50 174.8 -146.6 -176.9 -142.8 -153.6 -113.8
51 G A.G51 170.3 -147.3 -175.5 -148.2 -134.2 -122.1
52 U A.U52 160.3 -145.8 173.9 -144.3 -141.8 -119.6
53 G A.G53 174.9 -141.5 -167.2 -142.4 -124.7 -111.6
54 t A.5MU54 171.1 -129.2 -177.4 -122.6 -133.3 -76.4
55 P A.PSU55 165.3 -115.2 -173.6 -155.4 -112.1 145.1
56 C A.C56 31.4 -126.9 51.6 -124.1 25.3 -87.4
57 G A.G57 164.3 -142.5 -174.1 -131.9 -119.2 -113.8
58 a A.1MA58 -131.5 -108.7 -105.3 -171.2 -104.2 159.8
59 U A.U59 1.8 -119.4 26.8 -109.9 49.0 -56.9
60 C A.C60 -171.8 -40.7 -130.1 -68.5 -70.2 -35.8
61 C A.C61 122.4 -148.3 168.6 -144.1 -158.2 -117.4
62 A A.A62 173.0 -146.6 -176.9 -144.9 -142.0 -119.6
63 C A.C63 164.5 -148.3 177.9 -149.6 -143.9 -128.6
64 A A.A64 158.4 -151.0 168.5 -148.2 -154.8 -122.8
65 G A.G65 173.6 -147.3 -172.0 -145.4 -130.5 -121.2
66 A A.A66 177.6 -145.4 -170.1 -142.7 -133.5 -111.9
67 A A.A67 165.6 -149.3 -176.9 -149.8 -129.8 -126.7
68 U A.U68 168.9 -138.2 179.4 -136.1 -143.2 -96.5
69 U A.U69 165.6 -160.5 -176.0 -161.2 -118.8 -156.9
70 C A.C70 166.7 -146.2 173.6 -149.0 -171.6 -127.0
71 G A.G71 161.0 -143.0 174.0 -142.3 -146.3 -113.4
72 C A.C72 166.1 -141.5 -177.5 -141.9 -131.5 -110.2
73 A A.A73 167.6 -137.8 -177.2 -133.3 -127.1 -89.8
74 C A.C74 171.2 -122.1 -172.8 -116.5 -116.2 -72.1
75 C A.C75 174.9 106.5 -161.9 109.8 -102.9 -139.3
76 A A.A76 --- --- --- --- --- ---
******************************************************************************************
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 G A.G1 1.7 -23.4 35.1 -35.2 21.1 36.5 16.1 C3'-endo
2 C A.C2 1.6 -23.2 34.8 -34.8 20.9 36.2 16.1 C3'-endo
3 G A.G3 2.7 -25.1 36.8 -36.1 21.2 38.1 14.6 C3'-endo
4 G A.G4 -1.6 -22.3 36.3 -38.2 25.0 38.8 20.8 C3'-endo
5 A A.A5 10.1 -32.6 41.5 -36.6 16.7 41.7 4.8 C3'-endo
6 U A.U6 0.3 -24.0 37.3 -38.1 23.9 39.2 18.2 C3'-endo
7 U A.U7 -24.4 35.4 -32.4 18.9 3.3 35.4 156.1 C2'-endo
8 U A.U8 5.8 -28.7 39.7 -37.2 19.7 40.4 10.5 C3'-endo
9 A A.A9 -31.7 41.8 -35.6 18.1 8.4 41.2 149.8 C2'-endo
10 g A.2MG10 7.8 -28.0 36.7 -33.0 15.9 37.0 6.6 C3'-endo
11 C A.C11 1.2 -21.2 32.1 -32.5 19.8 33.5 16.8 C3'-endo
12 U A.U12 -4.6 -19.3 34.5 -37.9 26.7 38.1 25.2 C3'-endo
13 C A.C13 -3.4 -19.4 33.8 -36.4 25.1 36.9 23.7 C3'-endo
14 A A.A14 12.6 -30.8 36.8 -30.2 11.0 36.8 358.9 C2'-exo
15 G A.G15 1.9 -24.6 36.8 -36.8 22.2 38.3 16.0 C3'-endo
16 u A.H2U16 0.0 -18.7 29.2 -30.2 19.2 30.9 18.8 C3'-endo
17 u A.H2U17 23.0 -36.7 35.1 -23.2 0.2 37.0 341.4 C2'-exo
18 G A.G18 -27.9 39.5 -35.0 20.2 4.8 38.9 154.3 C2'-endo
19 G A.G19 -17.6 31.0 -31.9 23.1 -3.8 32.7 167.6 C2'-endo
20 G A.G20 6.6 -27.8 36.6 -34.2 17.5 37.0 8.7 C3'-endo
21 A A.A21 3.8 -25.0 35.1 -34.4 19.4 36.0 13.0 C3'-endo
22 G A.G22 16.4 -34.1 38.1 -29.5 8.3 38.3 353.8 C2'-exo
23 A A.A23 4.2 -26.6 37.4 -36.5 20.1 38.3 12.6 C3'-endo
24 G A.G24 3.9 -28.4 40.3 -39.3 22.4 41.5 13.4 C3'-endo
25 C A.C25 0.6 -24.5 37.8 -38.0 23.6 39.6 17.4 C3'-endo
26 g A.M2G26 6.3 -27.5 37.1 -34.7 17.9 37.6 9.3 C3'-endo
27 C A.C27 0.2 -23.5 36.5 -37.2 23.6 38.4 18.3 C3'-endo
28 C A.C28 6.6 -29.0 39.1 -36.3 18.8 39.6 9.2 C3'-endo
29 A A.A29 3.4 -26.6 38.4 -37.4 21.4 39.5 13.7 C3'-endo
30 G A.G30 2.6 -24.2 35.7 -34.9 20.4 36.9 14.5 C3'-endo
31 A A.A31 2.6 -24.0 35.0 -34.6 20.2 36.2 14.6 C3'-endo
32 c A.OMC32 -1.2 -21.7 35.1 -36.7 23.9 37.4 20.4 C3'-endo
33 U A.U33 3.5 -25.4 36.5 -35.3 20.1 37.5 13.3 C3'-endo
34 g A.OMG34 3.9 -22.7 32.2 -30.8 17.1 32.9 12.2 C3'-endo
35 A A.A35 -2.0 -19.9 32.7 -34.9 23.4 35.2 21.9 C3'-endo
36 A A.A36 -20.6 -7.3 30.6 -43.2 40.5 43.9 45.8 C4'-exo
37 g A.YYG37 2.1 -24.1 36.0 -35.6 21.0 37.4 15.4 C3'-endo
38 A A.A38 10.9 -30.3 37.6 -32.5 13.6 37.7 2.4 C3'-endo
39 P A.PSU39 2.1 -25.6 38.5 -38.4 22.8 40.0 15.8 C3'-endo
40 c A.5MC40 0.8 -22.5 34.6 -35.0 21.5 36.3 17.3 C3'-endo
41 U A.U41 3.8 -27.7 39.9 -38.6 22.0 41.0 13.4 C3'-endo
42 G A.G42 -1.7 -22.4 36.8 -38.6 25.4 39.4 20.9 C3'-endo
43 G A.G43 4.3 -27.6 39.1 -37.6 21.1 40.1 12.6 C3'-endo
44 A A.A44 1.0 -23.0 35.2 -35.4 21.6 36.8 16.9 C3'-endo
45 G A.G45 2.1 -24.3 35.7 -35.4 21.2 37.0 15.4 C3'-endo
46 g A.7MG46 -27.4 38.6 -34.7 19.7 4.7 38.5 154.5 C2'-endo
47 U A.U47 -20.9 34.8 -35.1 24.3 -2.2 36.4 164.9 C2'-endo
48 C A.C48 -25.6 38.4 -35.6 22.1 2.1 38.4 158.2 C2'-endo
49 c A.5MC49 5.8 -28.1 38.7 -36.0 19.1 39.3 10.1 C3'-endo
50 U A.U50 9.4 -32.2 41.0 -36.4 17.6 41.2 5.6 C3'-endo
51 G A.G51 4.9 -27.9 38.9 -36.8 20.3 39.7 11.5 C3'-endo
52 U A.U52 3.2 -28.5 41.4 -40.1 23.6 42.7 14.1 C3'-endo
53 G A.G53 -1.0 -23.1 37.0 -38.3 24.9 39.4 19.8 C3'-endo
54 t A.5MU54 -1.4 -22.2 35.9 -37.7 24.8 38.3 20.6 C3'-endo
55 P A.PSU55 6.2 -29.9 40.9 -38.3 20.4 41.5 10.1 C3'-endo
56 C A.C56 3.8 -25.3 35.7 -34.5 19.2 36.6 12.6 C3'-endo
57 G A.G57 4.0 -26.7 37.9 -36.5 20.6 38.9 12.8 C3'-endo
58 a A.1MA58 -24.3 38.4 -36.9 23.9 0.2 39.0 161.1 C2'-endo
59 U A.U59 -4.4 -18.3 31.8 -35.7 25.4 35.3 25.8 C3'-endo
60 C A.C60 -28.8 40.5 -36.4 21.2 4.7 40.3 154.8 C2'-endo
61 C A.C61 2.6 -25.5 36.8 -36.6 21.5 38.1 14.8 C3'-endo
62 A A.A62 5.9 -27.8 38.1 -35.4 18.8 38.7 9.9 C3'-endo
63 C A.C63 5.4 -27.3 37.5 -35.5 19.1 38.1 10.7 C3'-endo
64 A A.A64 4.1 -28.6 40.2 -38.8 22.2 41.2 12.9 C3'-endo
65 G A.G65 1.5 -26.6 39.5 -39.9 24.3 41.2 16.5 C3'-endo
66 A A.A66 -2.9 -21.6 36.5 -38.8 26.5 39.5 22.5 C3'-endo
67 A A.A67 2.4 -24.9 36.5 -36.1 21.4 37.8 15.0 C3'-endo
68 U A.U68 5.3 -28.4 39.5 -37.5 20.3 40.3 11.2 C3'-endo
69 U A.U69 2.9 -26.3 38.3 -37.9 22.3 39.6 14.7 C3'-endo
70 C A.C70 2.4 -25.9 38.7 -37.9 22.4 40.1 15.0 C3'-endo
71 G A.G71 3.7 -27.4 39.2 -38.3 21.8 40.3 13.5 C3'-endo
72 C A.C72 -0.6 -21.9 34.9 -36.2 23.1 37.0 19.5 C3'-endo
73 A A.A73 2.4 -25.4 37.3 -36.9 21.8 38.6 15.0 C3'-endo
74 C A.C74 4.4 -25.4 35.6 -34.0 18.6 36.4 11.8 C3'-endo
75 C A.C75 2.3 -22.5 33.1 -33.0 19.2 34.3 15.1 C3'-endo
76 A A.A76 -13.6 30.5 -34.8 27.7 -9.1 34.8 176.1 C2'-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 G A.G1 inc __ 0
2 C A.C2 33p 1a 0.935
3 G A.G3 33p 1a 0.868
4 G A.G4 33p 1a 0.842
5 A A.A5 33p 1a 0.847
6 U A.U6 33p 1a 0.664
7 U A.U7 32p 1b 0.803
8 U A.U8 23p 2a 0.509
9 A A.A9 32p 1[ 0.046
10 g A.2MG10 23p 2g 0.640
11 C A.C11 33p 1a 0.507
12 U A.U12 33p 1a 0.898
13 C A.C13 33t 1c 0.824
14 A A.A14 trig !! 0
15 G A.G15 33p 1a 0.484
16 u A.H2U16 trig !! 0
17 u A.H2U17 33t !! 0
18 G A.G18 32p 5p 0.026
19 G A.G19 22p 4b 0.512
20 G A.G20 23p 2a 0.623
21 A A.A21 33t !! 0
22 G A.G22 33t 1f 0.714
23 A A.A23 33p 1a 0.840
24 G A.G24 33p 1a 0.881
25 C A.C25 33p 1a 0.967
26 g A.M2G26 33p 1a 0.819
27 C A.C27 33p 1a 0.698
28 C A.C28 33p 1a 0.923
29 A A.A29 33p 1a 0.973
30 G A.G30 33p 1a 0.838
31 A A.A31 33p 1a 0.914
32 c A.OMC32 33p 1a 0.782
33 U A.U33 33p 1a 0.897
34 g A.OMG34 33p 1g 0.784
35 A A.A35 33p 1a 0.517
36 A A.A36 33p 1a 0.670
37 g A.YYG37 33p 1a 0.625
38 A A.A38 33p 1a 0.903
39 P A.PSU39 33p 1a 0.680
40 c A.5MC40 33p 1a 0.942
41 U A.U41 33p 1a 0.945
42 G A.G42 33p 1a 0.630
43 G A.G43 33p 1a 0.882
44 A A.A44 33p 1a 0.837
45 G A.G45 33p 1a 0.749
46 g A.7MG46 32p 1[ 0.849
47 U A.U47 22p 4p 0.589
48 C A.C48 22t 2u 0.283
49 c A.5MC49 23p 6d 0.520
50 U A.U50 33p 1a 0.656
51 G A.G51 33p 1a 0.981
52 U A.U52 33p 1a 0.945
53 G A.G53 33p 1a 0.896
54 t A.5MU54 33p 1a 0.720
55 P A.PSU55 33p 1a 0.586
56 C A.C56 33p 1g 0.894
57 G A.G57 33p 1a 0.837
58 a A.1MA58 32p 1[ 0.332
59 U A.U59 23p 4d 0.411
60 C A.C60 32p 1b 0.662
61 C A.C61 23p 2a 0.553
62 A A.A62 33p 1a 0.895
63 C A.C63 33p 1a 0.964
64 A A.A64 33p 1a 0.791
65 G A.G65 33p 1a 0.586
66 A A.A66 33p 1a 0.940
67 A A.A67 33p 1a 0.941
68 U A.U68 33p 1a 0.891
69 U A.U69 33p 1a 0.951
70 C A.C70 33p 1a 0.809
71 G A.G71 33p 1a 0.761
72 C A.C72 33p 1a 0.832
73 A A.A73 33p 1a 0.965
74 C A.C74 33p 1a 0.886
75 C A.C75 33p 1a 0.639
76 A A.A76 32t !! 0
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 RNA nts=76 G1aC1aG1aG1aA1aU1bU2aU1[A2gg1aC1aU1cC!!A1aG!!u!!u5pG4bG2aG!!A1fG1aA1aG1aC1ag1aC1aC1aA1aG1aA1ac1aU1gg1aA1aA1ag1aA1aP1ac1aU1aG1aG1aA1aG1[g4pU2uC6dc1aU1aG1aU1aG1at1aP1gC1aG1[a4dU1bC2aC1aA1aC1aA1aG1aA1aA1aU1aU1aC1aG1aC1aA1aC1aC!!A