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PDBsum entry 3pc7

Go to PDB code: 
protein Protein-protein interface(s) links
Ligase PDB id
3pc7
Jmol
Contents
Protein chains
81 a.a.
77 a.a.
Waters ×176
PDB id:
3pc7
Name: Ligase
Title: X-ray crystal structure of the DNA ligase iii-alpha brct dom
Structure: DNA ligase 3. Chain: a, b. Fragment: unp residues 924-1009. Synonym: DNA ligase iii, polydeoxyribonucleotide synthase [ engineered: yes. Mutation: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: lig3. Expressed in: escherichia coli. Expression_system_taxid: 469008.
Resolution:
1.65Å     R-factor:   0.143     R-free:   0.198
Authors: M.J.Cuneo,J.M.Krahn,R.E.London
Key ref: M.J.Cuneo et al. (2011). The structural basis for partitioning of the XRCC1/DNA ligase III-α BRCT-mediated dimer complexes. Nucleic Acids Res, 39, 7816-7827. PubMed id: 21652643
Date:
21-Oct-10     Release date:   15-Jun-11    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
P49916  (DNLI3_HUMAN) -  DNA ligase 3
Seq:
Struc:
 
Seq:
Struc:
1009 a.a.
81 a.a.*
Protein chain
Pfam   ArchSchema ?
P49916  (DNLI3_HUMAN) -  DNA ligase 3
Seq:
Struc:
 
Seq:
Struc:
1009 a.a.
77 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 3 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: Chains A, B: E.C.6.5.1.1  - Dna ligase (ATP).
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: ATP + (deoxyribonucleotide)(n) + (deoxyribonucleotide)(m) = AMP + diphosphate + (deoxyribonucleotide)(n+m)
ATP
+ (deoxyribonucleotide)(n)
+ (deoxyribonucleotide)(m)
= AMP
+ diphosphate
+ (deoxyribonucleotide)(n+m)
Molecule diagrams generated from .mol files obtained from the KEGG ftp site

 

 
    reference    
 
 
Nucleic Acids Res 39:7816-7827 (2011)
PubMed id: 21652643  
 
 
The structural basis for partitioning of the XRCC1/DNA ligase III-α BRCT-mediated dimer complexes.
M.J.Cuneo, S.A.Gabel, J.M.Krahn, M.A.Ricker, R.E.London.
 
  ABSTRACT  
 
The ultimate step common to almost all DNA repair pathways is the ligation of the nicked intermediate to form contiguous double-stranded DNA. In the mammalian nucleotide and base excision repair pathways, the ligation step is carried out by ligase III-α. For efficient ligation, ligase III-α is constitutively bound to the scaffolding protein XRCC1 through interactions between the C-terminal BRCT domains of each protein. Although structural data for the individual domains has been available, no structure of the complex has been determined and several alternative proposals for this interaction have been advanced. Interpretation of the models is complicated by the formation of homodimers that, depending on the model, may either contribute to, or compete with heterodimer formation. We report here the structures of both homodimer complexes as well as the heterodimer complex. Structural characterization of the heterodimer formed from a longer XRCC1 BRCT domain construct, including residues comprising the interdomain linker region, revealed an expanded heterodimer interface with the ligase III-α BRCT domain. This enhanced linker-mediated binding interface plays a significant role in the determination of heterodimer/homodimer selectivity. These data provide fundamental insights into the structural basis of BRCT-mediated dimerization, and resolve questions related to the organization of this important repair complex.