Fig 3c. The L,D transpeptidase ldt2 is required for covalent attachment of BpbA and BbpB to PG.

Stationary phase C. burnetii samples were frozen on a glow discharged Quantifoil™ R 2/2 grid using a Leica EM GP plunge freezer (Leica Microsystems, Wetzlar, Germany) set to a relative humidity of 100%. Grids were mounted in an autogrid assembly and cryo 2D images collected using a FEI Titan Krios 300kV FEG-TEM and a FEI Falcon II CMOS direct electron detection camera. Low dose images of 13e/A2 were captured at 6 µm defocus with a nominal magnification of 29 K which corresponds to a pixel size of 2.87 Å using a 70 µm objective aperture. OM vesiculation was quantified by imaging 50 bacterial cells per strain and is expressed as the percentage of bacteria with vesicles clearly attached to the bacterial OM.