Figure 6.

Peptide ligands differentially affect structures of Hop TPR mutants. Far UV-CD spectra were obtained for the TPR1 point mutant K73E(A), the TPR2 a point mutant R305E(B), and the TPR2b point mutant K429E(C) (in each case, 1μM purified, full-length recombinant protein) in the presence or the absence of synthetic peptide ligand (100 μM). The peptides used were control SRMAAVD (left-hand panels), Hsp90-related peptide SRMEEVD (middle panels), or Hsp70-related peptide PTIEEVD (right-hand panels). Spectra were obtained for mutant Hop (mutHop) forms alone (solid circles), peptide alone (open circles), and the mutHop +peptide mixtures (solid squares). Also, theoretical spectra were calculated by adding the spectra for mutHop alone and peptide alone (open squares). All measurements were made at pH 7.4, and the data shown are representative of three replicate experiments.