We have run an additional set of simulations on a slightly longer peptide with sequence Ace-XGPGXGGX-Nme (see Fig. ). In this case, the focus was on the stacking effect between their rings. In Figure we show the distribution of average distances between the heavy atoms in the rings of the studied peptides for the ff99SB and ff03 force fields, respectively. For convenience, we label the rings 1 to 3 going from the N to the C-terminus. As observed for the hexapeptide, the Mms-containing octapeptide behaves in a significantly different manner than its analogues favouring conformations in which Mms rings are stacked. As observed for the hexapeptide, the Mms ring stacking is less prevalent when using ff03. The unique behaviour triggered by the Mms residues is also present in the results of the other two ring pairs.