Reductive evolution of the mitochondrial processing peptidases of the unicellular parasites trichomonas vaginalis and giardia intestinalis.

ABSTRACT: Mitochondrial processing peptidases are heterodimeric enzymes (alpha/betaMPP) that play an essential role in mitochondrial biogenesis by recognizing and cleaving the targeting presequences of nuclear-encoded mitochondrial proteins. The two subunits are paralogues that probably evolved by duplication of a gene for a monomeric metallopeptidase from the endosymbiotic ancestor of mitochondria. Here, we characterize the MPP-like proteins from two important human parasites that contain highly reduced versions of mitochondria, the mitosomes of Giardia intestinalis and the hydrogenosomes of Trichomonas vaginalis. Our biochemical characterization of recombinant proteins showed that, contrary to a recent report, the Trichomonas processing peptidase functions efficiently as an alpha/beta heterodimer.

SUBMITTER: Smid O 

PROVIDER: S-EPMC2597178 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature