APPENDIX 1: Structures of Base Pairs Involving at Least Two Hydrogen Bonds

Abstract

The structures of the 28 possible base pairs that involve at least two hydrogen bonds are given in Figures 1–4 (for description, see Saenger, in Principles of nucleic acid structure, p. 120. Springer-Verlag [1984]). The non-Watson-Crick base pairs are called base-base mismatches, or internal loops of two nucleotides.