The biological assembly of OXA-48 reveals a dimer interface with high charge complementarity and very high affinity.

Many class D β-lactamases form dimers in solution. The functional basis of the dimerization of OXA-48-like class D β-lactamases is not known, but in order to understand the structural requirements for dimerization of OXA-48, we have characterized the dimer interface. Size exclusion chromatography, small angle X-ray scattering (SAXS), and nuclear magnetic resonance (NMR) were used to confirm the oligomeric state of OXA-48 in solution.