The structure of CCT-Hsc70 NBD suggests a mechanism for Hsp70 delivery of substrates to the chaperonin.
Chaperones, a group of proteins that assist the folding of other proteins, seem to work in a coordinated manner. Two major chaperone families are heat-shock protein families Hsp60 and Hsp70. Here we show for the first time the formation of a stable complex between chaperonin-containing TCP-1 (CCT) and Hsc70, two eukaryotic representatives of these chaperone families. This interaction takes place between the apical domain of the CCT beta subunit and the nucleotide binding domain of Hsc70, and may serve to deliver the unfolded substrate from Hsc70 to the substrate binding region of CCT. We also show that a similar interaction does not occur between their prokaryotic counterparts GroEL and DnaK, suggesting that in eukarya the two types of chaperones have evolved to a concerted action that makes the folding task more efficient.
Cuéllar
Jorge
J
Centro Nacional de Biotecnología, CSIC, Campus de la Universidad Autónoma de Madrid, Darwin, 3, 28049 Madrid, Spain.
Martín-Benito
Jaime
J
Scheres
Sjors H W
SH
Sousa
Rui
R
Moro
Fernando
F
López-Viñas
Eduardo
E
Gómez-Puertas
Paulino
P
Muga
Arturo
A
Carrascosa
José L
JL
Valpuesta
José M
JM
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry*; D018832:Molecular Chaperones / Q000737:chemistry; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
D029968:Escherichia coli Proteins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D018832:Molecular Chaperones; D020033:Protein Isoforms; D056404:Chaperonin Containing TCP-1; D018833:Chaperonins; C063842:dnaK protein, E coli