Protein
Heat shock protein 78, mitochondrial
Organism
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Function
Required, in concert with mitochondrial Hsp70 (SSC1), for the dissociation, resolubilization and refolding of aggregates of damaged proteins in the mitochondrial matrix after heat stress. May extract proteins from aggregates by unfolding and threading them in an ATP-dependent process through the axial channel of the protein hexamer, after which they can be refolded by the Hsp70 chaperone system. Required for resumption of mitochondrial respiratory function, DNA synthesis and morphology after heat stress. Its main role may be maintaining the molecular chaperone SSC1 in a soluble and functional state. Also required for the efficient degradation of proteins by matrix protease PIM1, independent on its protein remodeling activity.
Similarity
Belongs to the ClpA/ClpB family.
Sequence
MLRQATKAPIQKYLQRTQLLRRSTPRIYTIVQCKRSICSFNARPRVANKLLSDIKTNALNEVAISTCALKSSYGLPNFKRTYVQMRMDPNQQPEKPALEQFGTNLTKLARDGKLDPVIGRDEEIARAIQILSRRTKNNPCLIGRAGVGKTALIDGLAQRIVAGEVPDSLKDKDLVALDLGSLIAGAKYRGEFEERLKKVLEEIDKANGKVIVFIDEVHMLLGLGKTDGSMDASNILKPKLARGLRCISATTLDEFKIIEKDPALSRRFQPILLNEPSVSDTISILRGLKERYEVHHGVRITDTALVSAAVLSNRYITDRFLPDKAIDLVDEACAVLRLQHESKPDEIQKLDRAIMKIQIELESLKKETDPVSVERREALEKDLEMKNDELNRLTKIWDAERAEIESIKNAKANLEQARIELEKCQREGDYTKASELRYSRIPDLEKKVALSEKSKDGDKVNLLHDSVTSDDISKVVAKMTGIPTETVMKGDKDRLLYMENSLKERVVGQDEAIAAISDAVRLQRAGLTSEKRPIASFMFLGPTGTGKTELTKALAEFLFDDESNVIRFDMSEFQEKHTVSRLIGAPPGYVLSESGGQLTEAVRRKPYAVVLFDEFEKAHPDVSKLLLQVLDEGKLTDSLGHHVDFRNTIIVMTSNIGQDILLNDTKLGDDGKIDTATKNKVIEAMKRSYPPEFINRIDDILVFNRLSKKVLRSIVDIRIAEIQDRLAEKRMKIDLTDEAKDWLTDKGYDQLYGARPLNRLIHRQILNSMATFLLKGQIRNGETVRVVVKDTKLVVLPNHEEGEVVEEEAEK