Fig. 4

a Contour length percentage along a strand when summing up dissociated bubble segments from a certain threshold value (purple). Segments with consequential AT base paring along the λ-phage genome sequence (blue). The percentage of segments with odd complex adsorption pattern, derived from a statistical simulation (yellow). Percentage of areas where both conditions are met at the same time (green), fitting well to the actual observed bubble lengths. The dip at 1 bp accounts for the visual counting threshold. Inset: Distribution of melting bubble lengths. The relation between base pair and nm of 1 bp \(\widehat{=}\) 0.71 nm was determined from the interval distance in Fig. 2c. b Explanation model for the bubble formation. Top: Zigzag adsorption pattern of complex molecules. Middle: Reduced phosphate distance by partial A-to-B transformation introduces tensile stress on the base pairing. Bottom: Dehybridization of weaker bound AT-base pairs