
η/θ pseudo-torsion angle definitions of an RNA backbone conformation. η of a nucleotide n is a dihedral angle defined by the C4′-atom of the preceding nucleotide n-1, the C4′- and P-atoms of n and the P-atom of the succeeding nucleotide n+1. θ of n is the dihedral angle between the C4′- and P-atoms of n and n+1. Figure produced with UCSF Chimera (Pettersen et al. 2004).










