DnaJ Protein

DnaJ (HSP40)

Cat. Num. AAA634898

• Applications: Western Blot
• Purity: Highly Purified; 90%; determined by SDS-PAGE analysis.
• Synonyms: DnaJ; DnaJ (HSP40); DnaJ protein

• Purity/Purification: Highly Purified; 90%; determined by SDS-PAGE analysis.
• Form/Format: Supplied as a liquid in 50mM HEPES, pH 7.4, 300mM KCl, 2mM DTT and 10% glycerol.

• Applicable Applications for DnaJ protein: Western Blot (WB)
• Application Notes: DnaJ has a tendency to aggregate in solution with ionic strength lower than 0.1M KCI. Where lower salt conditions are required, addition of 0.05% Triton X-100 or Brij 58 is recommended. For Western Blot, on a 15-well Biorad minigel system, 50ng of protein per lane should be sufficient., , Storage and Stability:, For long-term storage, aliquot to avoid repeated freezing and thawing and freeze at -70 degree C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Aliquots are stable for at least 12 months.
• Preparation and Storage: -70 degree C

Related Product Information for DnaJ protein

DnaJ is a basic 41kD Escherichia coli heat shock protein which belongs to the molecular chaperone class of proteins. The E. coli dnaJ gene is located in an operon with dnaK (1). The sequence of the dnaJ gene shares identity with eukaryotic cytosol and endoplasmic reticulum DnaJ homologues. These homologues are known to be involved in i) protein folding, and membrane translocation of newly synthesized proteins, and ii) initiation of translation. The N-terminal domain of the DnaJ protein constitutes the most highly conserved domain and it is used as the signature sequence of DnaJ family members. This so-called "J" domain is important for DnaJ functions, including interaction with DnaK protein. Bacterial DnaJ protein acts synergistically with the bacterial chaperone DnaK (Hsp70 homologue) and the other co-chaperone GrpE in: 1) suppressing eukaryotic and prokaryotic polypeptide aggregation, thus promoting protein folding, 2) facilitating protein translocation through intracellular compartments or protein secretion, 3) reactivating ("repairing") some partially aggregated enzymes, such as E. coli RNAP and luciferase, 4) sequestering s32 E. coli transcription factor from the RNA polymerase core, and probably exposing it in such a way the s32 is efficiently proteolysed, 5) activating pre priming complex during initiation of lDNA replication, also involved in the initiation of DNA replication of the P1 and F plasmids. In these reactions, DnaJ protein facilitates binding of DnaK to its substrate by a tagging mechanism and/or by accelerating DnaK-catalyzed ATP hydrolysis promoting formation of DnaK-ADP form which possess a higher affinity for some (but not all) protein substrates. Ability to stimulate the ATPase activity of Hsp70 protein by DnaJ protein is also shared by some of its eukaryotic homologues, (i.e. S. cerevisiae YDJ1). Various Hsp70 proteins can perform specialized functions because they interact effectively with only certain DnaJ homologues. Recently published data suggest that DnaJ protein alone possess chaperone activity. It can bind tightly to some denatured proteins such as rhodanese or luciferase and in so doing, prevent their aggregation or misfolding.

Product Categories/Family for DnaJ protein

Molecular Biology; MB-Heat Shock Proteins

NCBI and Uniprot Product Information

• NCBI GI #: 825787
• Molecular Weight: ~43kD
• NCBI Official Full Name: DnaJ
• Protein Family: DnaJ

Uniprot Description

Participates actively in the response to hyperosmotic and heat shock by preventing the aggregation of stress-denatured proteins and by disaggregating proteins, also in an autonomous, DnaK-independent fashion. Unfolded proteins bind initially to DnaJ; upon interaction with the DnaJ-bound protein, DnaK hydrolyzes its bound ATP, resulting in the formation of a stable complex. GrpE releases ADP from DnaK; ATP binding to DnaK triggers the release of the substrate protein, thus completing the reaction cycle. Several rounds of ATP-dependent interactions between DnaJ, DnaK and GrpE are required for fully efficient folding. Also involved, together with DnaK and GrpE, in the DNA replication of plasmids through activation of initiation proteins.