1H and 15N magnetic resonance assignments, secondary structure, and tertiary fold of Escherichia coli DnaJ(1-78)

Biochemistry. 1995 Apr 25;34(16):5587-96. doi: 10.1021/bi00016a033.


We report the 1H and 15N chemical shift assignments along with an NMR-derived preliminary structure for DnaJ(1-78), a highly conserved N-terminal domain of DnaJ, the Escherichia coli Hsp40 homolog. This 9 kDa domain is believed to cooperate with DnaK, the E. coli Hsp70 homolog, in regulating a variety of cellular functions. Heteronuclear 3D NMR experiments were carried out on a uniformly 15N-labeled DnaJ(1-78), which is a stable, folded fragment. Standard 15N-edited NMR techniques afforded complete assignment of the backbone amide 1H and 15N pairs and partial assignment of the side-chain 1H and 15N atoms. The secondary structure of DnaJ(1-78) was determined from NOE connectivities obtained from 3D 15N-separated and 2D homonuclear NOESY spectra as well as 3JHNH alpha coupling constants obtained from a DQF-COSY spectrum and a 15N-edited HNHA experiment. The stability of secondary structural elements was assessed by monitoring amide exchange rates, and a model for the three-dimensional fold of these elements was derived from a set of long-range contacts extracted from homonuclear 2D NOESY experiments. The analysis indicates that DnaJ(1-78) is comprised of four alpha-helices and no beta-sheet with a short unstructured loop between antiparallel helices II and III. The shorter N-terminal and C-terminal helices make contacts with helices II and III at points well removed from the central loop. A discussion of how this preliminary structural model may explain mutation data from other laboratories is presented.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Cloning, Molecular
  • DNA Primers
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins
  • HSP40 Heat-Shock Proteins
  • Heat-Shock Proteins / chemistry*
  • Heat-Shock Proteins / metabolism
  • Hydrogen
  • Magnetic Resonance Spectroscopy / methods
  • Models, Structural
  • Molecular Sequence Data
  • Nitrogen Isotopes
  • Peptide Fragments / chemistry
  • Polymerase Chain Reaction
  • Protein Structure, Secondary*
  • Protein Structure, Tertiary*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism


  • Bacterial Proteins
  • DNA Primers
  • DnaJ protein, E coli
  • Escherichia coli Proteins
  • HSP40 Heat-Shock Proteins
  • Heat-Shock Proteins
  • Nitrogen Isotopes
  • Peptide Fragments
  • Recombinant Proteins
  • Hydrogen