1v97: Difference between revisions

Revision as of 16:32, 21 February 2008

Crystal Structure of Bovine Milk Xanthine Dehydrogenase FYX-051 bound form

OverviewOverview

Molybdenum is widely distributed in biology and is usually found as a mononuclear metal center in the active sites of many enzymes catalyzing oxygen atom transfer. The molybdenum hydroxylases are distinct from other biological systems catalyzing hydroxylation reactions in that the oxygen atom incorporated into the product is derived from water rather than molecular oxygen. Here, we present the crystal structure of the key intermediate in the hydroxylation reaction of xanthine oxidoreductase with a slow substrate, in which the carbon-oxygen bond of the product is formed, yet the product remains complexed to the molybdenum. This intermediate displays a stable broad charge-transfer band at approximately 640 nm. The crystal structure of the complex indicates that the catalytically labile Mo-OH oxygen has formed a bond with a carbon atom of the substrate. In addition, the MoS group of the oxidized enzyme has become protonated to afford Mo-SH on reduction of the molybdenum center. In contrast to previous assignments, we find this last ligand at an equatorial position in the square-pyramidal metal coordination sphere, not the apical position. A water molecule usually seen in the active site of the enzyme is absent in the present structure, which probably accounts for the stability of this intermediate toward ligand displacement by hydroxide.

About this StructureAbout this Structure

1V97 is a Single protein structure of sequence from Bos taurus with , , , , , , and as ligands. Active as Xanthine dehydrogenase, with EC number 1.17.1.4 Full crystallographic information is available from OCA.

ReferenceReference

The crystal structure of xanthine oxidoreductase during catalysis: implications for reaction mechanism and enzyme inhibition., Okamoto K, Matsumoto K, Hille R, Eger BT, Pai EF, Nishino T, Proc Natl Acad Sci U S A. 2004 May 25;101(21):7931-6. Epub 2004 May 17. PMID:15148401

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-[[Image:1v97.gif|left|200px]]<br /><applet load="1v97" size="450" color="white" frame="true" align="right" spinBox="true"
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 caption="1v97, resolution 1.94&Aring;" />
 '''Crystal Structure of Bovine Milk Xanthine Dehydrogenase FYX-051 bound form'''<br />
 ==Overview==
-Molybdenum is widely distributed in biology and is usually found as a, mononuclear metal center in the active sites of many enzymes catalyzing, oxygen atom transfer. The molybdenum hydroxylases are distinct from other, biological systems catalyzing hydroxylation reactions in that the oxygen, atom incorporated into the product is derived from water rather than, molecular oxygen. Here, we present the crystal structure of the key, intermediate in the hydroxylation reaction of xanthine oxidoreductase with, a slow substrate, in which the carbon-oxygen bond of the product is, formed, yet the product remains complexed to the molybdenum. This, intermediate displays a stable broad charge-transfer band at approximately, 640 nm. The crystal structure of the complex indicates that the, catalytically labile Mo-OH oxygen has formed a bond with a carbon atom of, the substrate. In addition, the MoS group of the oxidized enzyme has, become protonated to afford Mo-SH on reduction of the molybdenum center., In contrast to previous assignments, we find this last ligand at an, equatorial position in the square-pyramidal metal coordination sphere, not, the apical position. A water molecule usually seen in the active site of, the enzyme is absent in the present structure, which probably accounts for, the stability of this intermediate toward ligand displacement by, hydroxide.
+Molybdenum is widely distributed in biology and is usually found as a mononuclear metal center in the active sites of many enzymes catalyzing oxygen atom transfer. The molybdenum hydroxylases are distinct from other biological systems catalyzing hydroxylation reactions in that the oxygen atom incorporated into the product is derived from water rather than molecular oxygen. Here, we present the crystal structure of the key intermediate in the hydroxylation reaction of xanthine oxidoreductase with a slow substrate, in which the carbon-oxygen bond of the product is formed, yet the product remains complexed to the molybdenum. This intermediate displays a stable broad charge-transfer band at approximately 640 nm. The crystal structure of the complex indicates that the catalytically labile Mo-OH oxygen has formed a bond with a carbon atom of the substrate. In addition, the MoS group of the oxidized enzyme has become protonated to afford Mo-SH on reduction of the molybdenum center. In contrast to previous assignments, we find this last ligand at an equatorial position in the square-pyramidal metal coordination sphere, not the apical position. A water molecule usually seen in the active site of the enzyme is absent in the present structure, which probably accounts for the stability of this intermediate toward ligand displacement by hydroxide.
 ==About this Structure==
-V97 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CA, FES, MTE, MOS, FAD, FYX, ACY and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Xanthine_dehydrogenase Xanthine dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.1.4 1.17.1.4] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1V97 OCA].
+V97 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=FES:'>FES</scene>, <scene name='pdbligand=MTE:'>MTE</scene>, <scene name='pdbligand=MOS:'>MOS</scene>, <scene name='pdbligand=FAD:'>FAD</scene>, <scene name='pdbligand=FYX:'>FYX</scene>, <scene name='pdbligand=ACY:'>ACY</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Xanthine_dehydrogenase Xanthine dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.17.1.4 1.17.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1V97 OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Xanthine dehydrogenase]]
-[[Category: Eger, B.T.]]
+[[Category: Eger, B T.]]
 [[Category: Hille, R.]]
 [[Category: Matsumoto, K.]]
 [[Category: Nishino, T.]]
 [[Category: Okamoto, K.]]
-[[Category: Pai, E.F.]]
+[[Category: Pai, E F.]]
 [[Category: ACY]]
 [[Category: CA]]
@@ Line 33: / Line 33: @@
 [[Category: xanthine dehydrogenase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 04:31:06 2007''
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