A hallmark ofa-crystallin-type small heat shock proteins (sHsps) is their highly dynamic oligomeric structure which promotes intermolecular interactions involved in subunit exchange and substrate binding (chaperone-like activity). We studied the oligomeric features of two classes of bacterial sHsps by size exclusion chromatography and nanoelectro-spray mass of both classes formed large complexes that rapidly dissociated upon dilution and at physiologically relevant heat shock temperatures