cis-Effect of DnaJ on DnaK in ternary complexes with chimeric DnaK/DnaJ-binding peptides.
Chimeric peptides, comprising a DnaK-binding sequence of L-amino acid residues (motif k) and an exclusive DnaJ-binding sequence of D-amino acid residues (motif j) connected through a 22-residue linker, were examined as minisubstrates for the DnaK chaperone system. The DnaJ-stimulated ATPase activity of DnaK was three times higher in the presence of the chimeric peptides pjk or pkj than in the simultaneous presence of the corresponding single-motif peptides ala-p5 (k motif) plus D-p5 (j motif). Apparently, pjk and pkj mimic unfolded proteins by forming ternary (ATP x DnaK) x peptide x DnaJ complexes which favor cis-interaction of DnaJ with DnaK. Consistent with this interpretation, the specific stimulatory effect of the chimeric peptides was abolished by either single-motif peptide in excess.
Han
Wanjiang
W
Biochemisches Institut der Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
Christen
Philipp
P
D015081:2-Naphthylamine / Q000031:analogs & derivatives*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D004926:Escherichia coli / Q000235:genetics; D005456:Fluorescent Dyes; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D018832:Molecular Chaperones / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D013379:Substrate Specificity
D000596:Amino Acids; D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C038518:acrylodan; D015081:2-Naphthylamine; D000251:Adenosine Triphosphatases