FIG 6.

Stereo view of the superposition of frames from the molecular dynamics simulation of OXA-66 (blue) and OXA-109 (green) with acyl-doripenem from the crystal structure of OXA-24/40 (PDB 3PAE) (cyan; OXA-24/40 protein not shown). In OXA-66, I129 and W222 predominantly occupy positions that would be expected to clash extensively with the hydroxyethyl (I129) and pyrroline C-1 methyl (W222) groups of doripenem. The introduction of the P130Q substitution in OXA-109 leads to alternative conformations of both residues that greatly alleviate the steric clash.