The periplasmic chaperone SurA helps to transport nascent β-barrel proteins from the SEC translocase in the inner membrane, across the periplasm, to the outer membrane, in gram negative bacteria. SurA is known to function as a monomer, however we have observed that overexpressed periplasmic SurA forms a distinct, stable higher MW species, which may suggest a functional mechanism akin to other periplasmic chaperones. For example, Skp, has been shown to assemble into a multimeric protective cage around similar unfolded substrate proteins as it transports them to the OM from the SEC translocase. Characterisation of this multimerisation of SurA has been undertaken using size exclusion chromatography and SEC-MALS, thermal shift assays, and microscopy. The purified, overexpressed periplasmic SurA shows a distinct 450kDa species (~10-mer) that dissociates over time to a monomer. Given that this mulitmerisation is dependent upon periplasmic localisation of the protein, as an equivalent His-tagged version of the construct, without the pelB signal sequence, does not multimerise when overexpressed within the cytoplasm, this may be informative of its mode of action.