Divergent evolution of the M3A family of metallopeptidases in plants.
Plants, as stationary organisms, have developed mechanisms allowing them efficient resource reallocation and a response to changing environmental conditions. One of these mechanisms is proteome remodeling via a broad peptidase network present in various cellular compartments including mitochondria and chloroplasts. The genome of the model plant Arabidopsis thaliana encodes as many as 616 putative peptidase-coding genes organized in 55 peptidase families. In this study, we describe the M3A family of peptidases, which comprises four members: mitochondrial and chloroplastic oligopeptidase (OOP), cytosolic oligopeptidase (CyOP), mitochondrial octapeptidyl aminopeptidase 1 (Oct1) and plant-specific protein of M3 family (PSPM3) of unknown function. We have analyzed the evolutionary conservation of M3A peptidases across plant species and the functional specialization of the three distinct subfamilies. We found that the subfamily-containing OOP and CyOP-like peptidases, responsible for oligopeptide degradation in the endosymbiotic organelles (OOP) or in the cytosol (CyOP), are highly conserved in all kingdoms of life. The Oct1-like peptidase subfamily involved in pre-protein maturation in mitochondria is conserved in all eukaryotes, whereas the PSPM3-like protein subfamily is strictly conserved in higher plants only and is of unknown function. Specific characteristics within PSPM3 sequences, i.e. occurrence of a N-terminal transmembrane domain and amino acid changes in distal substrate-binding motif, distinguish PSPM3 proteins from other members of M3A family. We performed peptidase activity measurements to analyze the role of substrate-binding residues in the different Arabidopsis M3A paralogs.
Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden.
Beata
B
Kmiec
Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden.
Pedro F
PF
Teixeira
ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia, Australia.
Monika W
MW
Murcha
Department of Biochemistry and Biophysics, Stockholm University, Arrhenius Laboratories for Natural Sciences, Stockholm, Sweden.
Elzbieta
E
Glaser
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics; D005075:Biological Evolution; D002736:Chloroplasts / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D045726:Metalloproteases / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008958:Models, Molecular; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000201:enzymology* / Q000235:genetics; D000072417:Protein Domains; D020543:Proteome; D017422:Sequence Analysis, DNA
D010940:Plant Proteins; D020543:Proteome; D045726:Metalloproteases; D010447:Peptide Hydrolases; C028759:oligopeptidase