Fig. 1: Representation of the CTX-M-14 active site in the native state, the state with bound boric acid and the state with subsequently formed glycerol boric acid diester.

a Cartoon plot of the CTX-M-14 β-lactamase from Klebsiella pneumoniae and close-up views of the active site in surface representation of b the native constitution with a sulfate ion (SO4-A magenta; SO4-B yellow) in the anion-binding site, c with bound boric acid (BAB, pink) and a sulfate ion, and d with bound glycerol boric acid diester (GBE, pale green). BAB (c) and GBE (d) complex structures are shown with mixing delay times of 10 s, respectively.