Backbone dynamics of the N-terminal domain in E. coli DnaJ determined by 15N- and 13CO-relaxation measurements

Biochemistry. 1999 Aug 10;38(32):10567-77. doi: 10.1021/bi990263+.


The backbone dynamics of the N-terminal domain of the chaperone protein Escherichia coli DnaJ have been investigated using steady-state 1H-15N NOEs, 15N T1, T2, and T1 rho relaxation times, steady-state 13C alpha-13CO NOEs, and 13CO T1 relaxation times. Two recombinant constructs of the N-terminal domain of DnaJ have been studied. One, DnaJ(1-78), contains the most conserved "J-domain" of DnaJ, and the other, DnaJ(1-104), includes a glycine/phenylalanine rich region ("G/F" region) in addition to the "J-domain". DnaJ(1-78) is not capable of stimulating ATP hydrolysis by DnaK, despite the fact that all currently identified sites responsible for DnaJ-DnaK interaction are located in this region. DnaJ(1-104), on the other hand, retains nearly the full ATPase stimulatory activity of full length DnaJ. Recently, a structural analysis of these two molecules was presented in an effort to elucidate the origin of their functional differences [Huang, K., Flanagan, J. M., and Prestegard, J. H. (1999) Protein Science 8, 203-214]. Herein, an analysis of dynamic properties is presented in a similar effort. A generalized model-free approach with a full treatment of the anisotropic overall rotation of the proteins is used in the analysis of measured relaxation parameters. Our results show that internal motions on pico- to nanosecond time scales in the backbone of DnaJ(1-78) are reduced on the inclusion of the "G/F" region, while conformational exchange on micro- to millisecond time scales increases. We speculate that the enhanced flexibility of residues on the slow time scale upon the inclusion of the "G/F" region could be relevant to the ATPase stimulatory activity of DnaJ if an "induced-fit" mechanism applies to DnaJ-DnaK interactions.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anisotropy
  • Bacterial Proteins / chemistry*
  • Carbon Isotopes
  • Escherichia coli / chemistry*
  • Escherichia coli Proteins
  • HSP40 Heat-Shock Proteins
  • Heat-Shock Proteins / chemistry*
  • Models, Chemical
  • Models, Molecular
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular* / methods
  • Peptide Fragments / chemistry*
  • Protein Conformation
  • Thermodynamics


  • Bacterial Proteins
  • Carbon Isotopes
  • DnaJ protein, E coli
  • Escherichia coli Proteins
  • HSP40 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Nitrogen Isotopes
  • Peptide Fragments