Dna Ligase Iii Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| DNA Ligase III |
|---|
| Protein Name | DNA Ligase 3 |
| Gene | LIG3 |
| UniProt ID | P18858 |
| PDB IDs | 1T15, 3FC8, 5U07 |
| Molecular Weight | 110 kDa (nuclear), 95 kDa (mitochondrial) |
| Subcellular Localization | Nucleus, Mitochondria |
| Protein Family | DNA ligase family |
DNA Ligase III is a specialized DNA ligase that functions in multiple DNA repair pathways, including base excision repair (BER) and mitochondrial DNA repair. It is unique among DNA ligases for its dual localization to both the nucleus and mitochondria.
¶ Domain Architecture
- N-terminal BRCT Domain: Protein-protein interactions, XRCC1 binding (nuclear isoform)
- NAD-dependent DNA Ligase Domain: Catalytic core
- OB-fold Domain: DNA binding
- C-terminal Zinc Finger: Protein interaction
- DNA Ligase III-α: Nuclear isoform (~110 kDa), interacts with XRCC1
- DNA Ligase III-β: Testis-specific isoform
- Mitochondrial isoform: Alternative translation initiation (~95 kDa)
- ATP-dependent ligase
- Conserved adenylation domain
- Single-stranded DNA binding activity
- XRCC1 interaction through BRCT domain
- Final step in nick sealing after base removal
- Works with XRCC1 scaffold protein
- Essential for repair of oxidative DNA damage
¶ Single-Strand Break Repair
- Completes repair of SSBs
- Works with PARP1 and XRCC1
- Rapid response to endogenous DNA damage
¶ Mitochondrial DNA Maintenance
- Essential for mtDNA repair
- Required for mtDNA replication
- Maintains mitochondrial genome integrity
- Alternative NHEJ pathway
- Replication-related DNA repair
- Cell cycle regulation
- Germline mutations increase cancer risk
- Breast, ovarian, colorectal cancer association
- Impaired DNA repair capacity
- Progressive external ophthalmoplegia (PEO)
- Mitochondrial DNA depletion syndromes
- mtDNA deletion disorders
- Impaired BER in Alzheimer's disease neurons
- Oxidative stress vulnerability
- Parkinson's disease association
- Essential for neuronal survival
- Synthetic lethality with LIG3 deficiency
- Cancer therapy targeting DNA repair
- Combination strategies in development
- Novel approaches for mtDNA diseases
- Gene therapy potential
- Ellenberger T, Tomkinson AE (2008). "Eukaryotic DNA ligases: structural and functional insights." Annu Rev Biochem. PMID:18550802
- Lakshmipathy U, Campbell C (1999). "The human DNA ligase III gene encodes nuclear and mitochondrial proteins." Mol Cell Biol. PMID:10472098
- Georgiadis MM, et al. (2008). "Structure of human DNA ligase III." Acta Crystallogr D Biol Crystallogr. PMID:18854079
The study of Dna Ligase Iii Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.