Binding of ATP to heat shock protein 90: evidence for an ATP-binding site in the C-terminal domain.
The presence of a nucleotide binding site on hsp90 was very controversial until x-ray structure of the hsp90 N-terminal domain, showing a nonconventional nucleotide binding site, appeared. A recent study suggested that the hsp90 C-terminal domain also binds ATP (Marcu, M. G., Chadli, A., Bouhouche, I., Catelli, M. G., and Neckers, L. M. (2000) J. Biol. Chem. 275, 37181-37186). In this paper, the interactions of ATP with native hsp90 and its recombinant N-terminal (positions 1-221) and C-terminal (positions 446-728) domains were studied by isothermal titration calorimetry, scanning differential calorimetry, and fluorescence spectroscopy. Results clearly demonstrate that hsp90 possesses a second ATP-binding site located on the C-terminal part of the protein. The association constant between this domain of hsp90 and ATP-Mg and a comparison with the binding constant on the full-length protein are reported for the first time. Secondary structure prediction revealed motifs compatible with a Rossmann fold in the C-terminal part of hsp90. It is proposed that this potential Rossmann fold may constitute the C-terminal ATP-binding site. This work also suggests allosteric interaction between N- and C-terminal domains of hsp90.
Garnier
Cyrille
C
CNRS-UPR 1524, ICGM, 24 rue du Faubourg Saint Jacques, Paris 75014, France.
Lafitte
Daniel
D
Tsvetkov
Philipp O
PO
Barbier
Pascale
P
Leclerc-Devin
Jocelyne
J
Millot
Jean-Marc
JM
Briand
Claudette
C
Makarov
Alexander A
AA
Catelli
Maria G
MG
Peyrot
Vincent
V
D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism*; D000495:Allosteric Site; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002151:Calorimetry; D002152:Calorimetry, Differential Scanning; D002645:Chickens; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013552:Swine; D013696:Temperature
D018841:HSP90 Heat-Shock Proteins; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D008274:Magnesium