1PT3: Crystal Structures Of Nuclease-Cole7 Complexed With Octamer Dna

The bacterial toxin ColE7 bears an HNH motif which has been identified in hundreds of prokaryotic and eukaryotic endonucleases, involved in DNA homing, restriction, repair, or chromosome degradation. The crystal structure of the nuclease domain of ColE7 in complex with a duplex DNA has been determined at 2.5 A resolution. The HNH motif is bound at the minor groove primarily to DNA phosphate groups at and beyond the 3' side of the scissile phosphate, with little interaction with ribose groups and bases. This result provides a structural basis for sugar- and sequence-independent DNA recognition and the inhibition mechanism by inhibitor Im7, which blocks the substrate binding site but not the active site. Structural comparison shows that two families of endonucleases bind and bend DNA in a similar way to that of the HNH ColE7, indicating that endonucleases containing a "betabetaalpha-metal" fold of active site possess a universal mode for protein-DNA interactions.
PDB ID: 1PT3Download
MMDB ID: 74182
PDB Deposition Date: 2003/6/22
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Escherichia coli str. K-12 substr. W3110
Similar Structures:
Biological Unit for 1PT3: octameric; determined by author
Molecular Components in 1PT3
Label Count Molecule
Proteins (2 molecules)
Colicin E7
Molecule annotation
Nucleotide(1 molecule)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB