Precipitated by adding protein A-Sepharose. After subjecting the precipitate to SDS-PAGE, 32 and DnaK were detected by CBB staining, and DnaJ was detected by immunoblotting with anti-DnaJ serum. Pull-down assays for the interaction between 32 and DnaKHis or DnaJ-His were performed using Ni2 -NTA-agarose. DnaK-His was preincubated in Buffer D (20 mM Tris-HCl (pH 7.5), 100 mM KCl, 10 glycerol, 5 mM