Identification of the peptide binding domain of hsc70. 18-Kilodalton fragment located immediately after ATPase domain is sufficient for high affinity binding.
Recombinant hsc70, a purified glutathione S-transferase (GST) fusion protein containing the C-terminal domain of hsc70 (GST-Ct), and an internal 18-kDa polypeptide located immediately after the 44-kDa ATPase domain of hsc70 were investigated for their peptide binding properties. The dissociation constants of the S-peptide for native hsc70 (Kd = 5-8 microM), GST-Ct (Kd = 6.5 microM), and the 18-kDa fragment (Kd = 8.1 microM) are virtually identical. In addition, polylysine and (Pro-Pro-Gly)5 do not show high affinity toward hsc70, GST-Ct, and the 18-kDa fragment, whereas peptide GT4 and P3a show comparably high affinity toward these polypeptides. These observations indicate that the peptide binding domain of hsc70 is confined in the internal 18-kDa fragment.
Wang
T F
TF
Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China.
Chang
J H
JH
Wang
C
C
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000378:metabolism*; D017931:DNA Primers; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism
D002352:Carrier Proteins; D017931:DNA Primers; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D010446:Peptide Fragments; D000251:Adenosine Triphosphatases