Bulges are common features of folded RNA structures. The RNA axial kinking caused by bulges has been confirmed by many experiments. Usually, a kinking angle ζ and a bending angle θ are used to describe the kinking and twisting of RNA molecules containing bulges. Here, we present two additional angles (twist angle ζ1, twist angle ζ2) to describe the deformation of RNA helices induced by bulge loops because only two angles (a kinking angle ζ and a bending angle θ) are not enough to define the deformation of RNA induced by bulges. © 2002 Elsevier Science B.V. All rights reserved.
Liang, C. R., & Liu, C. Q. (2002). Additional angles to calculate the deformation of RNA helices induced by bulge loops. Journal of Molecular Structure: THEOCHEM, 617(1–3), 63–67. https://doi.org/10.1016/S0166-1280(02)00404-9