7V98

Crystal Structure of the Dimeric EcHsp60

Summary for 7V98

• Entry DOI: 10.2210/pdb7v98/pdb
• Descriptor: 60 kDa chaperonin (2 entities in total)
• Functional Keywords: hsp60, homodimer, inactive form, chaperone
• Biological source: Epinephelus coioides
• Total number of polymer chains: 2
• Total formula weight: 124723.31

Authors

Lai, M.C.,Lin, S.M. (deposition date: 2021-08-24, release date: 2022-08-31, Last modification date: 2023-11-29)

Primary citation

Lai, M.C.,Cheng, H.Y.,Lew, S.H.,Chen, Y.A.,Yu, C.H.,Lin, H.Y.,Lin, S.M.
Crystal structures of dimeric and heptameric mtHsp60 reveal the mechanism of chaperonin inactivation.
Life Sci Alliance, 6:-, 2023

PubMed Abstract: Mitochondrial Hsp60 (mtHsp60) plays a crucial role in maintaining the proper folding of proteins in the mitochondria. mtHsp60 self-assembles into a ring-shaped heptamer, which can further form a double-ring tetradecamer in the presence of ATP and mtHsp10. However, mtHsp60 tends to dissociate in vitro, unlike its prokaryotic homologue, GroEL. The molecular structure of dissociated mtHsp60 and the mechanism behind its dissociation remain unclear. In this study, we demonstrated that mtHsp60 (EcHsp60) can form a dimeric structure with inactive ATPase activity. The crystal structure of this dimer reveals symmetrical subunit interactions and a rearranged equatorial domain. The α4 helix of each subunit extends and interacts with its adjacent subunit, leading to the disruption of the ATP-binding pocket. Furthermore, an RLK motif in the apical domain contributes to stabilizing the dimeric complex. These structural and biochemical findings provide new insights into the conformational transitions and functional regulation of this ancient chaperonin.

PubMed: 36973006
DOI: 10.26508/lsa.202201753

Experimental method

X-RAY DIFFRACTION (2.35 Å)