Figure 2.

Structural basis for AmpC_EC inhibition by bicyclic boronates. (a) reaction between sp²-hybridized bicyclic boronates and SBLs give a serine-bonded anionic sp³-hybridized species; (b) structures of serine-bonded sp³ forms of the bicyclic boronates; (c–e) active site views of complexes of AmpC_EC with CB2, CB3, and TAN. Hydrogen-bonding interactions are shown in colored dashes, distances are in Å; (f) overlay of active site views, color coding as in (c–e). Note that the Q120 side chain is rotated in AmpC_EC-CB2 structure (highlighted in dark red); it is unclear whether this is induced by binding of CB2, or due to the crystallization conditions (see text).