At the same time, insertion of a GC pair into the middle of the AT tract does not show this effect, however when the junction folds at this position, it resides at this position much longer time in comparison to the folding at AT pairs.
While the loss of UNG mainly affected SHM at GC base pairs, inactivation of the mismatch repair system (MMR) was found to diminish hypermutation at AT pairs (Rada et al. 1998; Wiesendanger et al. 2000).
Analysis of binding to DNA by footprinting showed high affinity for compounds derived from 2,7-dihydrophenanthrene dicarboxylic acid and a predominant selectivity for AT rich regions containing at least 4 AT pairs but with the ability to span up to two CG base pairs.
The melting of DNA also requires the breakage of Watson-Crick hydrogen bonds (H-bonds) and it is well known that GC pairs (3 H-bonds) are stronger than AT pairs (2 H-bonds).
The genome of DapuNPV is 136,761 bp long with AT pairs content 45.6%%.
n AT pairs with one member in and the other in.
Intergenic regions of DapuNPV consist of 12,853 bp (9.4 % of whole genome) with AT pairs content calculated to be 59.8%%.
The increasing intensity of this band in the case of DNA modification by 1,4-naphthoquinone results in disruption of hydrogen bonds in GC and AT pairs.
GC pairs differ from AT pairs since guanine binds to cytosine with three hydrogen bonds, while adenine forms only two bonds with thymine.
The AT pairs content is 45.6%% and classifies DapuNPV in the vicinity of OpMNPV with its 44.9 %, while the highest AT pairs content among the members of Baculoviridae family is found in CrleGV (Cryptophlebia leucotreta granulovirus) - 67.6 % and the lowest in LdMNPV - 42.5 %.
