1ql0: Difference between revisions

[[Image:1ql0.jpg|left|200px]]<br /><applet load="1ql0" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1QL0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Serratia_marcescens Serratia marcescens] with <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Serratia_marcescens_nuclease Serratia marcescens nuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.30.2 3.1.30.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QL0 OCA].  

[[Category: Betzel, C H.]]

[[Category: Mikhailov, A M.]]

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