title: A novel mitochondrial and chloroplast peptidasome, PreP.
abstract: A novel mitochondrial and chloroplast peptidasome, the Presequence Protease (PreP) degrades organellar targeting peptides as well as other unstructured peptides up to 65 amino acid residues in length. PreP belongs to the pitrilysin oligopeptidase family (M16C) containing an inverted zinc-binding motif. The crystal structure of Arabidopsis thaliana PreP, AtPreP, refined at 2.1 Å, revealed a novel mechanism of proteolysis in which two halves of the enzyme connected by a hinge region enclose a large catalytic chamber opening and closing in response to peptide binding. Double knock-out mutant of AtPreP1 and AtPreP2 results in a severe phenotype, including decreased size and growth rate, chlorosis and organellar abnormalities, such as altered chloroplast starch content, partial loss of the integrity of the inner mitochondrial membrane and reduced mitochondrial respiration. PreP homologues are also present in yeast and humans. Interestingly, human PreP has been associated with Alzheimer's disease as it is responsible for degradation of amyloid-β peptide in brain mitochondria.
authors: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Science, Stockholm University, SE-10691 Stockholm, Sweden.
authors: Beata
authors: B
authors: Kmiec
authors: Elzbieta
authors: E
authors: Glaser
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D019069:Cell Respiration; D060365:Chloroplast Proteins / Q000235:genetics / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008928:Mitochondria / Q000201:enzymology*; D051336:Mitochondrial Membranes / Q000201:enzymology; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D021381:Protein Transport; D059748:Proteolysis; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D060365:Chloroplast Proteins; D024101:Mitochondrial Proteins; D010447:Peptide Hydrolases; C511107:presequence protease PreP, Arabidopsis