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A novel mitochondrial and chloroplast peptidasome, PreP
Author(s) -
Kmiec Beata,
Glaser Elzbieta
Publication year - 2012
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2011.01531.x
Subject(s) - chloroplast , mitochondrion , oligopeptidase , biochemistry , biology , proteolysis , mutant , arabidopsis thaliana , amino acid , inner mitochondrial membrane , microbiology and biotechnology , enzyme , gene
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, At PreP, 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 At PreP1 and At PreP2 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.