The yeast Hsp110, Sse1p, exhibits high-affinity peptide binding.
Hsp110s are divergent relatives of Hsp70 chaperones that hydrolyze ATP. Hsp110s serve as Hsp70 nucleotide exchange factors and act directly to maintain polypeptide solubility. To date, the impact of peptide binding on Hsp110 ATPase activity is unknown and an Hsp110/peptide affinity has not been measured. We now report on a peptide that binds to the yeast Hsp110, Sse1p, with a K(D) of approximately 2 nM. Surprisingly, the binding of this peptide fails to stimulate Sse1p ATP hydrolysis. Moreover, an Hsp70-binding peptide is unable to associate with Sse1p, suggesting that Hsp70s and Hsp110s possess partially distinct peptide recognition motifs.
University of Pittsburgh, Department of Biological Sciences, 274A Crawford Hall, Pittsburgh, PA 15260, USA.
Jennifer L
JL
Goeckeler
Anthony P
AP
Petruso
Julia
J
Aguirre
Cristina C
CC
Clement
Gabriela
G
Chiosis
Jeffrey L
JL
Brodsky
D000251:Adenosine Triphosphatases / Q000378:metabolism; D050957:HSP110 Heat-Shock Proteins / Q000378:metabolism*; D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D050957:HSP110 Heat-Shock Proteins; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D010455:Peptides; C494656:SSE1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases