Under normal conditions, DnaK functions to ensure proper folding of nascent proteins as well as “correct” the folding of any misfolded proteins. Under stress conditions this function becomes even more critical as there are far more proteins that become misfolded and require chaperone protection with subsequent intervention to re-fold into a native conformation.
DnaK is the 70 kDa heat shock protein in bacteria, homologous to human Hsp70. However, as opposed to humans where many Hsp70 alleles exist and can overtake the functions if one is eliminated, in bacteria there is only one DnaK that has to carry all shock response actions.
When exposed to DPCs, DnaK function is inhibited, resulting in misfolded/dysfunctional proteins, making the bacterial cell more prone to both external stressors (e.g., antibiotics) as well as internal terminal pathways, such as apoptosis. Without functional proteins in a native conformation, critical resistance mechanisms (e.g., efflux pumps) become compromised causing previously antibiotic-resistant bacteria to become antibiotic-sensitive once more.