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Search The CSA
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Catalytic Site Atlas

CSA LITERATURE entry for 1dnk

E.C. namedeoxyribonuclease I
SpeciesBos taurus (Bovine)
E.C. Number (IntEnz) 3.1.21.1
CSA Homologues of 1dnk1atn,2a3z,2a40,2a41,2a42,2d1k,2dnj,3cjc,3dni,
CSA Entries With UniProtID P00639
CSA Entries With EC Number 3.1.21.1
PDBe Entry 1dnk
PDBSum Entry 1dnk
MACiE Entry M0041

Literature Report

IntroductionDNase I is a vertebrate enzyme that cleaves double stranded DNA to 5'-phosphodinucleotide and 5'-phospho-oligonucletide end-products. DNase I requires calcium and magnesium for full activity. It is a glycoprotein that causes single-stranded nicks on double-stranded DNA. DNase I shares structural homology to the Human Apurinic/Apyrimidinic endonuclease and Exonuclease III. These three enzymes also share similar mechanisms of DNA cleavage.
Mechansim The reaction involves an in-line attack at the DNA phosphorus group by a water molecule. H252 may act as a general base to abstract a proton from a water molecule opposite the O3' atom. Subsequent attack at the phosphorus group with inversion of its configuration gives rise to a penta-covalent state that may be stabilised by the metal ion. H134 is in an ideal position to protonate the leaving O3'. The metal ion may also be important for the correct positioning of the phosphate group.

Catalytic Sites for 1dnk

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
AspA212234macie:sideChain
HisA134156macie:sideChain
GluA78100macie:sideChain
HisA252274macie:sideChain

Literature References

Notes:
Jones SJ
Site-directed mutagenesis of the catalytic residues of bovine pancreatic deoxyribonuclease I.
J Mol Biol 1996 264 1154-1163
PubMed: 9000637
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