FIG 10.
SQ109 binds to the SQS active site. (A) T. cruzi SQS + FSPP + SQ109 complex (PDB ID 3WSB). Lime green, protein; purple, FSPP; cyan, SQ109. (B) Ligands in superimposed CrtM + FSPP and TcSQS + FSPP + SQ109 complexes. Green, FSPP in CrtM; purple, FSPP in TcSQS; cyan, SQ109 in TcSQS. (C) Ligands in superimposed human SQS + SQ109 (PDB ID 3WSA) and TcSQS + FSPP + SQ109 complexes. Orange, SQ109 in HsSQS; purple, FSPP in TcSQS; cyan, SQ109 in TcSQS. Although it is a very modest SQS inhibitor, SQ109 might be a lead for the development of inhibitors that target prenyltransferases and the Δψm, in basically the same way that amiodarone and dronedarone do.