PDBsum entry 3uj3

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protein links
Recombination PDB id
Protein chain
124 a.a.
PDB id:
Name: Recombination
Title: Crystal structure of the synaptic tetramer of the g-segment (gin)
Structure: DNA-invertase. Chain: x. Engineered: yes. Mutation: yes
Source: Enterobacteria phage mu. Organism_taxid: 10677. Gene: gin, 51. Expressed in: escherichia coli. Expression_system_taxid: 562
3.51Å     R-factor:   0.259     R-free:   0.289
Authors: C.J.Ritacco,J.Wang,S.Kamtekar,T.A.Steitz
Key ref: C.J.Ritacco et al. (2013). Crystal structure of an intermediate of rotating dimers within the synaptic tetramer of the G-segment invertase. Nucleic Acids Res, 41, 2673-2682. PubMed id: 23275567
07-Nov-11     Release date:   05-Dec-12    
Supersedes: 3plo
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Protein chain
Pfam   ArchSchema ?
P03015  (DNIV_BPMU) -  Serine recombinase gin
193 a.a.
124 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 2 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     host cell cytoplasm   1 term 
  Biological process     DNA recombination   3 terms 
  Biochemical function     recombinase activity     4 terms  


Nucleic Acids Res 41:2673-2682 (2013)
PubMed id: 23275567  
Crystal structure of an intermediate of rotating dimers within the synaptic tetramer of the G-segment invertase.
C.J.Ritacco, S.Kamtekar, J.Wang, T.A.Steitz.
The serine family of site-specific DNA recombination enzymes accomplishes strand cleavage, exchange and religation using a synaptic protein tetramer. A double-strand break intermediate in which each protein subunit is covalently linked to the target DNA substrate ensures that the recombination event will not damage the DNA. The previous structure of a tetrameric synaptic complex of γδ resolvase linked to two cleaved DNA strands had suggested a rotational mechanism of recombination in which one dimer rotates 180° about the flat exchange interface for strand exchange. Here, we report the crystal structure of a synaptic tetramer of an unliganded activated mutant (M114V) of the G-segment invertase (Gin) in which one dimer half is rotated by 26° or 154° relative to the other dimer when compared with the dimers in the synaptic complex of γδ resolvase. Modeling shows that this rotational orientation of Gin is not compatible with its being able to bind uncleaved DNA, implying that this structure represents an intermediate in the process of strand exchange. Thus, our structure provides direct evidence for the proposed rotational mechanism of site-specific recombination.