1f0o
PVUII ENDONUCLEASE/COGNATE DNA COMPLEX (GLUTARALDEHYDE-CROSSLINKED CRYSTAL) AT PH 7.5 WITH TWO CALCIUM IONS AT EACH ACTIVE SITE
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OverviewOverview
Restriction endonucleases differ in their use of metal cofactors despite, having remarkably similar folds for their catalytic regions. To explore, this, we have characterized the interaction of endonuclease PvuII with the, catalytically incompetent cation Ca(2+). The structure of a, glutaraldehyde-crosslinked crystal of the endonuclease PvuII-DNA complex, determined in the presence of Ca(2+) at a pH of approximately 6.5, supports a two-metal mechanism of DNA cleavage by PvuII. The first Ca(2+), position matches that found in all structurally examined endonucleases, while the second position is similar to that of EcoRV but is distinct from, that of BamHI and BglI. The location of the second metal in PvuII, unlike, that in BamHI/BglI, permits no direct interaction between the second metal, and the O3' oxygen leaving group. However, the interactions between the, DNA scissile phosphate and the metals, the first metal and the attacking, water, and the attacking water and DNA are the same in PvuII as they are, in the two-metal models of BamHI and BglI, but are distinct from the, proposed three-metal or the two-metal models of EcoRV.
About this StructureAbout this Structure
1F0O is a Single protein structure of sequence from Proteus vulgaris with CA as ligand. Active as Type II site-specific deoxyribonuclease, with EC number 3.1.21.4 Full crystallographic information is available from OCA.
ReferenceReference
PvuII endonuclease contains two calcium ions in active sites., Horton JR, Cheng X, J Mol Biol. 2000 Jul 28;300(5):1049-56. PMID:10903853
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