A co-affinity assay coupled to downstream LC-MS analyses were used to investigate the effect of linker mutations on the DnaK interactome as previously described3. The purified recombinant forms of DnaK and DnaKLS were immobilized (as bait) by His-tag affinity on HisPur cobalt resin suspended in TBS (10 mM Tris-HCl pH 7.5, 50 mM NaCl and 10 Mm imidazole) and incubated at 4 °C for 4 hours with gently rocking motion to allow maximum binding.