Crystal structure of the nuclease domain of ColE7 (H545Q mutant) in complex with an 18-bp duplex DNACrystal structure of the nuclease domain of ColE7 (H545Q mutant) in complex with an 18-bp duplex DNA

Structural highlights

2ivh is a 3 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.8Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CEA7_ECOLX This plasmid-coded bactericidal protein is an endonuclease active on both single- and double-stranded DNA but with undefined specificity. Colicins are polypeptide toxins produced by and active against E.coli and closely related bacteria.

Evolutionary Conservation

 

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Nonspecific endonucleases hydrolyze DNA without sequence specificity but with sequence preference, however the structural basis for cleavage preference remains elusive. We show here that the nonspecific endonuclease ColE7 cleaves DNA with a preference for making nicks after (at 3'O-side) thymine bases but the periplasmic nuclease Vvn cleaves DNA more evenly with little sequence preference. The crystal structure of the 'preferred complex' of the nuclease domain of ColE7 bound to an 18 bp DNA with a thymine before the scissile phosphate had a more distorted DNA phosphate backbone than the backbones in the non-preferred complexes, so that the scissile phosphate was compositionally closer to the endonuclease active site resulting in more efficient DNA cleavage. On the other hand, in the crystal structure of Vvn in complex with a 16 bp DNA, the DNA phosphate backbone was similar and not distorted in comparison with that of a previously reported complex of Vvn with a different DNA sequence. Taken together these results suggest a general structural basis for the sequence-dependent DNA cleavage catalyzed by nonspecific endonucleases, indicating that nonspecific nucleases could induce DNA to deform to distinctive levels depending on the local sequence leading to different cleavage rates along the DNA chain.

Structural basis for sequence-dependent DNA cleavage by nonspecific endonucleases.,Wang YT, Yang WJ, Li CL, Doudeva LG, Yuan HS Nucleic Acids Res. 2007;35(2):584-94. Epub 2006 Dec 15. PMID:17175542[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Wang YT, Yang WJ, Li CL, Doudeva LG, Yuan HS. Structural basis for sequence-dependent DNA cleavage by nonspecific endonucleases. Nucleic Acids Res. 2007;35(2):584-94. Epub 2006 Dec 15. PMID:17175542 doi:10.1093/nar/gkl621

2ivh, resolution 2.80Å

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