Bacterial Hsp90 mediates the degradation of aggregation-prone Hsp70-Hsp40 substrates preferentially by the HslUV protease

Whereas in eukaryotic cells Hsp90s are extensively studied in bacteria, the function of Hsp90 (HtpG) and its functional relationship with Hsp70 (DnaK) remains unknown. To uncover physiological processes depending on HtpG and DnaK, we performed comparative quantitative proteomic analyses of insoluble and total protein fractions from unstressed wild type E. coli, and from knockout mutants ΔdnaKdnaJ (ΔKJ), ΔhtpG (ΔG) and ΔdnaKdnaJΔhtpG (ΔKJG) and compared their growth rates under heat-stress also with ΔdnaKdnaJΔhslV.