Taken all together, MD simulations of LANA-DBMnucleosome complexes postulate that LANA-DBM bivalently binds to histone acidic patch and DNA, mainly major groove at SHL -4.5, within a nucleosome, and G5 is the prime candidate position for BAHA conjugating to realize H2BK43/K46 selective acetylation. Interestingly, in the distance tracking analysis, we found that the extent of histone Lys residue fluctuation varied from residue to residue. The root mean square fluctuation (RMSF) analysis showed that H2BK43 was less flexible than H2BK46 or other Lys residues (Table ). The small fluctuation of H2BK43 was also apparent by the narrow distribution in the distance parameter (Figure ). As described in the next section, fluctuation is the third determinant of regioselectivity.