The human mitochondrial Hsp60 in the APO conformation forms a stable tetradecameric complex.
Adrian S EnriquezHumberto M RojoJay M BhattSudheer Kumar MoluguZacariah L HildenbrandRicardo A BernalPublished in: Cell cycle (Georgetown, Tex.) (2017)
The human mitochondrial chaperonin is a macromolecular machine that catalyzes the proper folding of mitochondrial proteins and is of vital importance to all cells. This chaperonin is composed of 2 distinct proteins, Hsp60 and Hsp10, that assemble into large oligomeric complexes that mediate the folding of non-native polypeptides in an ATP dependent manner. Here, we report the bacterial expression and purification of fully assembled human Hsp60 and Hsp10 recombinant proteins and that Hsp60 forms a stable tetradecameric double-ring conformation in the absence of co-chaperonin and nucleotide. Evidence of the stable double-ring conformation is illustrated by the 15 Å resolution electron microscopy reconstruction presented here. Furthermore, our biochemical analyses reveal that the presence of a non-native substrate initiates ATP-hydrolysis within the Hsp60/10 chaperonin to commence protein folding. Collectively, these data provide insight into the architecture of the intermediates used by the human mitochondrial chaperonin along its protein folding pathway and lay a foundation for subsequent high resolution structural investigations into the conformational changes of the mitochondrial chaperonin.
Keyphrases
- heat shock protein
- endothelial cells
- heat shock
- molecular dynamics simulations
- heat stress
- oxidative stress
- single molecule
- high resolution
- induced pluripotent stem cells
- pluripotent stem cells
- poor prognosis
- induced apoptosis
- binding protein
- machine learning
- mass spectrometry
- small molecule
- signaling pathway
- electron microscopy
- artificial intelligence
- protein protein
- anaerobic digestion