1ql0
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| , resolution 1.1Å | |||||||
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| Ligands: | |||||||
| Activity: | Serratia marcescens nuclease, with EC number 3.1.30.2 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
SM ENDONUCLEASE FROM SERATIA MARCENSCENS AT ATOMIC RESOLUTION
OverviewOverview
The three-dimensional crystal structure of Serratia marcescens endonuclease has been refined at 1.1 A resolution to an R factor of 12.9% and an R(free) of 15.6% with the use of anisotropic temperature factors. The model contains 3694 non-H atoms, 715 water molecules, four sulfate ions and two Mg(2+)-binding sites at the active sites of the homodimeric protein. It is shown that the magnesium ion linked to the active-site Asn119 of each monomer is surrounded by five water molecules and shows an octahedral coordination geometry. The temperature factors for the bound Mg(2+) ions in the A and B subunits are 7.08 and 4.60 A(2), respectively, and the average temperature factors for the surrounding water molecules are 12.13 and 10.3 A(2), respectively. In comparison with earlier structures, alternative side-chain conformations are defined for 51 residues of the dimer, including the essential active-site residue Arg57. A plausible mechanism of enzyme function is proposed based on the high-resolution S. marcescens nuclease structure, the functional characteristics of the natural and mutational forms of the enzyme and consideration of its structural analogy with homing endo-nuclease I-PpoI.
About this StructureAbout this Structure
1QL0 is a Single protein structure of sequence from Serratia marcescens. Full crystallographic information is available from OCA.
ReferenceReference
Atomic structure of the Serratia marcescens endonuclease at 1.1 A resolution and the enzyme reaction mechanism., Shlyapnikov SV, Lunin VV, Perbandt M, Polyakov KM, Lunin VY, Levdikov VM, Betzel C, Mikhailov AM, Acta Crystallogr D Biol Crystallogr. 2000 May;56(Pt 5):567-72. PMID:10771425
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