a) The CLPP homologues from P. anserina, Homo sapiens, C. elegans and E. coli display a conserved distribution of the canonical catalytic residues Ser, His and Asp. Additionally, all eukaryotic CLPPs contain a mitochondrial targeting sequence (MTS). The length of the different CLPP homologues varies from 207 amino acids in E. coli to 277 amino acids in H. sapiens. The amino-acid sequence of PaCLPP shares 57%, 60% and 58% similarity with that of HsCLPP, CeCLPP-1, and EcCLPP, respectively. ( b) Southern blot analysis of HindIII digested genomic DNA from wild-type and Δ PaClpP. The PaClpP-specific hybridization probe detects the 4995-bp fragment containing PaClpP only in wild-type genomic DNA. A 2454-bp fragment containing the phleomycin resistance gene ( ble) is detected by a ble-specific hybridization probe only in genomic DNA of Δ PaClpP. ( c) Western blot analysis of mitochondrial protein extracts from wild-type and Δ PaClpP. The PaCLPP-specific antibody detects the ~25-kDa PaCLPP monomer only in the wild-type sample. PaPORIN (PaPOR) was detected as a loading control. ( d) Growth rate of wild-type (0.60±0.04; n=59) and Δ PaClpP (0.58±0.04; n=55; P=0.07 by two-tailed Wilcoxon rank-sum test) isolates at 27 °C. Data given in parentheses are mean growth rate±s.e. in centimetres per day. ( e) Female fertility of wild-type (100±14.7; n=11) and Δ PaClpP (126.1±20.3; n=11; P=0.26 by two-tailed Wilcoxon rank-sum test) isolates at 27 °C. Data given in parentheses are mean female fertility±s.e. in percentage. ( f) Lifespan of wild-type (21.7±0.5; n=59), Δ PaClpP (37.1±1.5; n=57; P=5.8E-18), Δ PaIap (37.9±1.8; n=15; P=2.7E-09) and Δ PaClpP/Δ PaIap (70.6±3.4; n=90; P=8.5E-25) isolates at 27 °C. Data given in parentheses are mean lifespan±s.e. in days. P-values were determined in comparison with the wild-type sample by two-tailed Wilcoxon rank-sum test.