The pharma-interface and pharma-motifs of Isoleucyl-tRNA synthetase-Mupirocin complex. (A) The pharma-motif superimposition between Isoleucyl-tRNA synthetase and its polypharmacological target, Methionyl-tRNA synthetase, is well aligned. These two proteins are belonging to the different structure families and the pharma-motifs are the color segments. (B) Interacting residues are highly conserved in these pharma-motifs. The ligands are colored by magenta. (C) Pharma-motif 1 and the corresponding PROSITE motif, PS00178. (D) Pharma-motif 4 is the ATP binding motif and involves KMSKS loop with two conserved residues (G601 and N602). These two residues stabilize the KMSKS loop by using hydrogen bonds (green line) with residue K598.