More than just a ticket canceller: the mitochondrial processing peptidase tailors complex precursor proteins at internal cleavage sites.

ABSTRACT: Most mitochondrial proteins are synthesized as precursors that carry N-terminal presequences. After they are imported into mitochondria, these targeting signals are cleaved off by the mitochondrial processing peptidase (MPP). Using the mitochondrial tandem protein Arg5,6 as a model substrate, we demonstrate that MPP has an additional role in preprotein maturation, beyond the removal of presequences. Arg5,6 is synthesized as a polyprotein precursor that is imported into mitochondria and subsequently separated into two distinct enzymes. This internal processing is performed by MPP, which cleaves the Arg5,6 precursor at its N-terminus and at an internal site. The peculiar organization of Arg5,6 is conserved across fungi and reflects the polycistronic arginine operon in prokaryotes. MPP cleava

SUBMITTER: Friedl J 

PROVIDER: S-EPMC8734313 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature