2num: Difference between revisions

[[Image:2num.jpg|left|200px]]<br /><applet load="2num" size="350" color="white" frame="true" align="right" spinBox="true"  

The Rieske [2Fe-2S] iron-sulfur protein of cytochrome bc(1) functions as the initial electron acceptor in the rate-limiting step of the catalytic reaction. Prior studies have established roles for a number of conserved residues that hydrogen bond to ligands of the [2Fe-2S] cluster. We have constructed site-specific variants at two of these residues, measured their thermodynamic and functional properties, and determined atomic resolution X-ray crystal structures for the native protein at 1.2 A resolution and for five variants (Ser-154--&gt;Ala, Ser-154--&gt;Thr, Ser-154--&gt;Cys, Tyr-156--&gt;Phe, and Tyr-156--&gt;Trp) to resolutions between 1.5 A and 1.1 A. These structures and complementary biophysical data provide a molecular framework for understanding the role hydrogen bonds to the cluster play in tuning thermodynamic properties, and hence the rate of this bioenergetic reaction. These studies provide a detailed structure-function dissection of the role of hydrogen bonds in tuning the redox potentials of [2Fe-2S] clusters.

2NUM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides] with <scene name='pdbligand=FES:'>FES</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Ubiquinol--cytochrome-c_reductase Ubiquinol--cytochrome-c reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.10.2.2 1.10.2.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2NUM OCA].  

[[Category: Crofts, A R.]]

[[Category: Nair, S K.]]

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