Stressgen, BioMol, Alexis Corporation, Assay Designs, Alexis

protein

GrpE (E. coli), (recombinant)

ADI-SPP-650-C

25 µg

ADI-SPP-650-C

GrpE (E. coli), (recombinant)

Protein

25 µg

10631262, 10100860

GrpE is an acidic 24 kDa protein which is encoded by a monocistronic Escherichia coli gene (located at 56 min.) which is under the control of both s32 and s70 transcription factors. The GrpE protein is a so-called cochaperone because it is known to assist the DnaK (Hsp70) protein to effectively carry out DnaK-dependent chaperone activity (i.e. protein folding, protein transport, disaggregation of heat inactivated proteins, activation of mutant protein). This auxiliary role is critical to DnaK’s chaperone biology since the grpE gene could not be deleted in a wild type background unless the host E. coli were previously adapted for deletions of the DnaK gene through the accumulation of extragenic suppressors. Also, in vitro these two proteins functionally interact; GrpE protein forms a salt resistant complex with DnaK protein, which is disrupted by ATP. It is suggested that DnaK and DnaJ assist protein folding by stabilizing an intermediate conformation; where as the GrpE protein, in an ATP-dependent reaction release partially folded protein from the DnaK/J complex and transfer this immature protein to the GroEL/ES chaperone complex to finish the protein folding reaction. In some cases DnaK/GrpE could act independently of DnaJ chaperone protein: the "inactive" form of DnaA5 mutant protein is activated in the presence of the DnaK and GrpE proteins, and the presence of DnaJ inhibit this reaction. GrpE cochaperone protein assists DnaK chaperone during two crucial steps: binding to protein substrate and releasing DnaK chaperone from the complex with substrate.

HSP70 cofactor, Nucleotide exchange factor, HSP24, Heat shock protein 24

≥90% (SDS-PAGE; Western blot)

Liquid. In 25mM HEPES, pH 7.6, containing 50mM potassium chloride and 5.0% glycerol.

Western blot control.

WB, in vitro Assay

-80°C