Glycosidic torsion angle, variable

A statistical survey of crystal structures of nucleic acid constituents has led to the proposal that a full description of nucleoside molecular geometry can be given in terms of four parameters the phase angle of pseudorotation, P, the puckering amplitude, the conformation of the side-chain, 5, and the glycosidic torsional angle, X these allow the variability of bond and torsion angles to be described. ... 

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