Printable factfile
Gene Information
Names
HUGO name: LIG4
Alias(es):
- Sealase
- DNA joinase
- DNA repair enzyme
- Ligase IV, DNA, ATP-dependent
- Polydeoxyribonucleotide synthase
- Polynucleotide ligase
- DNA ligase IV
- EC 6.5.1.1
- Polydeoxyribonucleotide synthase [ATP]
Variations / Mutations
Other gene-based resources
Protein Information
Description
Protein function:
Efficiently joins single-strand breaks in a double-stranded polydeoxynucleotide in an ATP-dependent reaction. Involved in DNA nonhomologous end joining (NHEJ) required for double-strand break repair and V(D)J recombination. Binds to XCRCC4. The LIG4-XRCC4 complex is responsible for the NHEJ ligation step, and XRCC4 enhances the joining activity of LIG4. Binding of the LIG4-XRCC4 complex to DNA ends is dependent on the assembly of the DNA-dependent protein kinase complex DNA-PK to these DNA ends.
Catalytic activity:
ATP + {deoxyribonucleotide}(n) + {deoxyribonucleotide}(m) = AMP + diphosphate + {deoxyribonucleotide}(n+m)
Subunit:
The LIG4-XRCC4 complex has probably a 1:2 stochiometry. The LIG4-XRCC4 heteromer associates in a DNA-dependent manner with the DNA-dependent protein kinase complex DNA-PK, formed by the KU p70/p86 dimer (g22p1/g22p2) and PRKDC.
Subcellular location:
Nuclear
Tissue specificity:
Testis, thymus, prostate and heart.
Similarity:
Belongs to the ATP-dependent DNA ligase family.
Structures (PDB)
| 1IK9 | Crystal Structure Of A Xrcc4-DNA Ligase IV Complex |
Domains
BRCT 1 domain: 587-676
BRCT 2 domain: 741-844
Other features
Amp binding site: 206
Other related resourses:
- PIR: I37079
- InterPro: IPR001357; BRCT
- InterPro: IPR000977; DNA_ligase
- Pfam: PF00533; BRCT
- Pfam: PF01068; DNA_ligase
- Pfam: PF04679; DNA_ligase_A_C
- Pfam: PF04675; DNA_ligase_A_N
- SMART: SM00292; BRCT
- PROSITE: PS50172; BRCT
- PROSITE: PS00697; DNA_LIGASE_A1
- PROSITE: PS00333; DNA_LIGASE_A2
- PROSITE: PS50160; DNA_LIGASE_A3
Expression
Expression pattern for human
| Tissue | Expression (%) | Clones |
|---|---|---|
| juvenile granulosa tumor | 18.16 | 1:2159 |
| thymus | 17.92 | 1:2187 |
| fetal liver | 8.83 | 1:4439 |
| pituitary | 6.80 | 1:5766 |
| corresponding non cancerous liver tissue | 5.94 | 2:13205 |
| glioblastoma | 5.54 | 1:7072 |
| leukopheresis | 5.05 | 1:7769 |
| chondrosarcoma grade II | 4.90 | 1:8000 |
| cochlea | 4.55 | 1:8607 |
| total brain | 3.70 | 1:10594 |
| juvenile granulosa tumor | 18.16 | 1:2159 |
| thymus | 17.92 | 1:2187 |
| fetal liver | 8.83 | 1:4439 |
| pituitary | 6.80 | 1:5766 |
| corresponding non cancerous liver tissue | 5.94 | 2:13205 |
| glioblastoma | 5.54 | 1:7072 |
| leukopheresis | 5.05 | 1:7769 |
| chondrosarcoma gradeII | 4.90 | 1:8000 |
| cochlea | 4.55 | 1:8607 |
| total brain | 3.70 | 1:10594 |