Table 2. Steps and pseudo steps exhibited by the homoduplexes with mismatches.

Nomenclature	Description
L = GpC=GC/GC	Standard basepair step
M = CpG=CG/CG
N = GG/CC=CC/GG
LC = GC/CC=CC/GC	Pseudo GpC step L containing intrahelical C mismatches
MC = CG/CC=CC/CG	Pseudo CpG step M containing intrahelical C mismatches
W = CC/CC	Pseudo step containing two intrahelical C mismatches
LL = GC//GC MM = CG//CG	Pseudo steps where the two basepairs of the step are simply stacked on top of each other but not covalently linked along the backbone (because C’s have been extruded)
LLC = GC//CC=CC//GC MMC = CG//CC=CC//CG	Pseudo steps like LC and MC, but the G–C or C–G basepairs are not covalently linked to the C intrahelical mismatches (because one of the two C–C mismatches has been extruded)