FIG 7.

In silico simulation of E. coli PBP1b (PDB ID: 3VMA) in complex with albofungins 1 to 3. (A) Conserved motifs are highlighted on the top of the sequence alignment for TGase domains of monofunctional TGase and bifunctional TGase domains of S. aureus MtgA (SA-MtgA), S. aureus PBP2 (SA-PBP2), A. aeolicus PBP1a (AA-PBP1a), A. baumannii PBP1b (AB-PBP1b), and E. coli PBP1b (EC-PBP1b). Black bold lines underscore conserved motifs, and red triangles stand for key residues forming hydrogen bonds to albofungins. The multisequence alignment was generated by using ClustalW version 2.0. (B) Superposition of compounds 1 to 3 and moenomycin A, the only antibiotic that binds to the TGase domain in PBP1b. (C) Compounds 1 to 3 and moenomycin A in the active site. (D) Compounds 1 to 3 interact with key active-site residues; gray, moenomycin A; orange, albofungin (compound 1); yellow, chloroalbofungin (compound 2); pink, bromoalbofungin (compound 3). The default analytical distance is set at <5Å for the ligand with its interacting residues. Figures were prepared by using PyMOL.