Complex formation of HipB, HipAN and HipAC. (a) Purification of tertiary mixtures using size exclusion chromatography. Elution locations of standard proteins with known mass are shown with vertical arrows. The two major peaks of the protein mixture are emphasized with star symbols. (b) SDS–PAGE analysis of size exclusion chromatography fractions. Star symbols indicate the lanes to which the starred peaks belong. (c) SDS–PAGE analysis of chemical crosslinking of H. influenzae HipB using DMA and DMS crosslinkers. Experimental conditions are indicated above and the corresponding multimer form is labelled on the right side of the gel.