THIS IS THE INDEX FOR THE LIBRARY: torsions

                 THE NUCLEIC ACID DATABASE PROJECT

This library contains tables and conformation rings for torsion
angles for A, B, and Z DNAs.  The tables are present in both
ascii and PostScript versions.  The conformation rings are 
PostScript files.  

NOTE ON GRAPHICS: TORSION ANGLE CONFORMATION RINGS:

	PostScript graphics files containing conformation rings (1)
depicting the occurrences of nucleic acid backbone and side group
torsion angles {P-O5' alpha (omega), O5'-C5' beta (phi), C5'-C4' gamma
(psi), C4'-C3' delta (psi prime), C3'-O3' epsilon (phi prime), O3'-P
zeta (omega prime), glycosyl chi} corresponding to the different DNA
and RNA structures present in the Nucleic Acid Database have been
recently put into the electronic library.
	The conformation rings describe the occurrences of the six
backbone torsion angles and the glycosal rotation of the various DNAs
and RNAs in a series of concentric rings.  The NDB file name is
indicated at the bottom of each figure.  Each ring is scaled from 0
degrees to 360 degrees and the occurrence of a particular torsion
angle is noted by a radial line in the appropriate angular location.
Multiple lines in a given ring represent the various values of a
particular torsion of the selected structure.  The sectors with dense
lines readily reveal the preferred conformation range of the
corresponding torsions.  The distribution of the radial lines in a
given ring reflects the flexibility of the specified torsion.  Visual
comparison of the approximate preferences and the flexibility of
different torsion angles is also made easy by the patterns of lines in
different concentric rings.  Overall comparisons of the conformation
rings of different structures provide direct information on their
similarities and differences.


(1) A. R. Srinivasan and Wilma K. Olson, Nucleic Acids Research, 8,
2307-2329 (1980).



TABLE 9:  TORSION ANGLES

Torsion angles are given for A, B, and Z DNAs.  Each of these tables
contain the following torsion angles for each residue in the
structure:

       TORSIONS:              GREEK SYMBOL CONVENTIONS:

(n-1)O3'- P-   O5'-  C5'    	Alpha		Omega
     P-   O5'- C5'-  C4'  	Beta		Phi
     O5'- C5'- C4'-  C3'	Gamma		Psi
     C5'- C4'- C3'-  O3'  	Delta		Psi prime
     C4'- C3'- O3'-  P      	Epsilon		Phi prime
     C3'- O3'- P  -  O5'(n+1)	Zeta		Omega prime
     O4'- C1'- N1/N9-C2/C4 	Chi		Chi
     O4'- C1'- N1/N9-C6/C8      Chi             Chi  
     C4'- O4'- C1'-  C2'        Nu0     
     O4'- C1'- C2'-  C3'        Nu1
     C1'- C2'- C3'-  C4'        Nu2
     C2'- C3'- C4'-  O4'        Nu3
     C3'- C4'- O4'-  C1'        Nu4

The tables are located in the following files in the library:

File name in        File name in       Contents:
torsions:           torsions:

--------------      ----------------   --------------------------------------

torsion_<ndbid>.ps  torsion_<ndbid>.ascii  - Torsion angles for the
                                             structure whose NDB file
                                             name is substituted for
                                             the word <ndbid>.

For example:

torsion_addb01.ps   torsion_addb01.ascii   - Torsion angles for
					     structure addb01.
                                                                  
GRAPH 1:  TORSION ANGLE CONFORMATION RINGS

These graphs display the six backbone torsion angles and the glycosyl
torsion.  Each of the seven concentric rings displays one torsion
angle (alpha, beta, gamma, etc), and depicts that angle for each
residue in the structure.  This way, the distribution of torsion
angles can be seen at a glance.  (Please read the note given above)

Conformation rings are given for A, B, and Z DNAs.  Each of these
graphs contain the following torsion angles for each residue in the
structure:

       TORSIONS:              GREEK SYMBOL CONVENTIONS:

(n-1)O3'- P-   O5'-  C5'    	Alpha		Omega
     P-   O5'- C5'-  C4'  	Beta		Phi
     O5'- C5'- C4'-  C3'	Gamma		Psi
     C5'- C4'- C3'-  O3'  	Delta		Psi prime
     C4'- C3'- O3'-  P      	Epsilon		Phi prime
     C3'- O3'- P  -  O5'(n+1)	Zeta		Omega prime
     O4'- C1'- N1/N9-C2/C4 	Chi		Chi

The graphs are located in the following files in the library:

File name in        Contents:
torsions:          

--------------      --------------------------------------

ring_<ndbid>.ps    - Torsion angles for the
                      structure whose NDB file
                      name is substituted for
                      the word <ndbid>.

For example:

ring_addb01.ps     - Torsion angles for
                      structure addb01.