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EXOG, a novel paralog of Endonuclease G in higher eukaryotes
- Source :
- Nucleic Acids Research
- Publication Year :
- 2008
-
Abstract
- Evolutionary conserved mitochondrial nucleases are involved in programmed cell death and normal cell proliferation in lower and higher eukaryotes. The endo/exonuclease Nuc1p, also termed ‘yeast Endonuclease G (EndoG)’, is a member of this class of enzymes that differs from mammalian homologs by the presence of a 5′–3′ exonuclease activity in addition to its broad spectrum endonuclease activity. However, this exonuclease activity is thought to be essential for a function of the yeast enzyme in DNA recombination and repair. Here we show that higher eukaryotes in addition to EndoG contain its paralog ‘EXOG’, a novel EndoG-like mitochondrial endo/exonuclease. We find that during metazoan evolution duplication of an ancestral nuclease gene obviously generated the paralogous EndoG- and EXOG-protein subfamilies in higher eukaryotes, thereby maintaining the full endo/exonuclease activity found in mitochondria of lower eukaryotes. We demonstrate that human EXOG is a dimeric mitochondrial enzyme that displays 5′–3′ exonuclease activity and further differs from EndoG in substrate specificity. We hypothesize that in higher eukaryotes the complementary enzymatic activities of EndoG and EXOG probably together account for both, the lethal and vital functions of conserved mitochondrial endo/exonucleases.
- Subjects :
- Exonuclease
Exonucleases
Molecular Sequence Data
ENDOG
Mitochondrion
medicine.disease_cause
Polymorphism, Single Nucleotide
Cell Line
Substrate Specificity
Mitochondrial Proteins
03 medical and health sciences
Endonuclease
Catalytic Domain
Genetics
medicine
Animals
Humans
Histidine
Amino Acid Sequence
Endodeoxyribonucleases
Gene
Phylogeny
030304 developmental biology
0303 health sciences
Nuclease
Mutation
biology
Nucleic Acid Enzymes
030302 biochemistry & molecular biology
Endonucleases
Cell biology
Mitochondrial Membranes
biology.protein
Dimerization
Hydrophobic and Hydrophilic Interactions
Sequence Alignment
Subjects
Details
- ISSN :
- 13624962
- Volume :
- 36
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Nucleic acids research
- Accession number :
- edsair.doi.dedup.....4bdfa7f24c4211c346144dc26b2fa3ab