Mitochondrial co-chaperone which forms a complex with prohibitins to regulate cardiolipin remodeling (By similarity). May be a component of the PAM complex, a complex required for the translocation of transit peptide-containing proteins from the inner membrane into the mitochondrial matrix in an ATP-dependent manner. May act as a co-chaperone that stimulate the ATP-dependent activity (By similarity). {ECO:0000250|UniProtKB:Q07914, ECO:0000250|UniProtKB:Q9CQV7}. This is the function of DNAJC19 (DnaJ heat shock protein family (Hsp40) member C19, Ensembl gene identifier ENSG00000205981).