Structural highlights
Function
[DNAK_ECOLI] Plays an essential role in the initiation of phage lambda DNA replication, where it acts in an ATP-dependent fashion with the DnaJ protein to release lambda O and P proteins from the preprimosomal complex. DnaK is also involved in chromosomal DNA replication, possibly through an analogous interaction with the DnaA protein. Also participates actively in the response to hyperosmotic shock.[HAMAP-Rule:MF_00332]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
How substrate affinity is modulated by nucleotide binding remains a fundamental, unanswered question in the study of 70 kDa heat shock protein (Hsp70) molecular chaperones. We find here that the Escherichia coli Hsp70, DnaK, lacking the entire alpha-helical domain, DnaK(1-507), retains the ability to support lambda phage replication in vivo and to pass information from the nucleotide binding domain to the substrate binding domain, and vice versa, in vitro. We determined the NMR solution structure of the corresponding substrate binding domain, DnaK(393-507), without substrate, and assessed the impact of substrate binding. Without bound substrate, loop L3,4 and strand beta3 are in significantly different conformations than observed in previous structures of the bound DnaK substrate binding domain, leading to occlusion of the substrate binding site. Upon substrate binding, the beta-domain shifts towards the structure seen in earlier X-ray and NMR structures. Taken together, our results suggest that conformational changes in the beta-domain itself contribute to the mechanism by which nucleotide binding modulates substrate binding affinity.
Structural insights into substrate binding by the molecular chaperone DnaK.,Pellecchia M, Montgomery DL, Stevens SY, Vander Kooi CW, Feng HP, Gierasch LM, Zuiderweg ER Nat Struct Biol. 2000 Apr;7(4):298-303. PMID:10742174[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Pellecchia M, Montgomery DL, Stevens SY, Vander Kooi CW, Feng HP, Gierasch LM, Zuiderweg ER. Structural insights into substrate binding by the molecular chaperone DnaK. Nat Struct Biol. 2000 Apr;7(4):298-303. PMID:10742174 doi:http://dx.doi.org/10.1038/74062
