DnaJ E.Coli

DnaJ proteins contain a J-domain, which is crucial for their interaction with the ATPase domain of DnaK (HSP70). This interaction is essential for the protein’s chaperone activity. The J-domain stimulates the ATPase activity of DnaK, which in turn helps in the folding and assembly of newly synthesized proteins and the refolding of misfolded proteins .

In E. coli, DnaJ works in conjunction with DnaK and GrpE to form a chaperone system that assists in protein folding under both normal and stress conditions. This system is vital for the survival of the bacteria, especially under conditions of heat shock or other environmental stresses .

Recombinant DnaJ (HSP40) from E. coli is typically produced as a single, non-glycosylated polypeptide chain. It is often tagged with a His-tag to facilitate purification. The recombinant protein is expressed in E. coli and purified using affinity chromatography. The purity of the recombinant protein is usually greater than 95%, as determined by SDS-PAGE .

Recombinant DnaJ (HSP40) is used in various research applications, including studies on protein folding, stress response, and chaperone activity. It is also used in the production of antibodies and as a standard in biochemical assays .

Lyophilized recombinant DnaJ (HSP40) is stable for up to 12 months when stored at -20°C to -80°C. Reconstituted protein solution can be stored at 4-8°C for 2-7 days. For long-term storage, aliquots of the reconstituted protein should be stored at -20°C or below .