Figure 5.

Best-ranked docking pose of the thiophene derivative SST0682. The phenyl rings at the amide spacer and at the thiophene nucleus are involved in π–cation interactions with the guanidino moiety of Arg223 and the ammonium group of Lys209, respectively. Moreover, the carbonyl oxygen of the ester side chain makes a hydrogen bond with His220 of the zinc chelating architecture. The trichloromethyl side chain is accommodated within the region occupied by the dimethyl moiety of SST0704 (Figure 6). The structure of SST0682 is represented by thick sticks, amino acid side chains by thin sticks, the zinc ion as a blue sphere, hydrogen bonds as dotted yellow lines, and π–cation interaction as dotted green lines.