1phw: Difference between revisions

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[[Image:1phw.gif|left|200px]]<br /><applet load="1phw" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

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

caption="1phw, resolution 2.36Å" />

'''Crystal structure of KDO8P synthase in its binary complex with substrate analog 1-deoxy-A5P'''<br />

==Overview==

The enzyme 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS), catalyses the condensation of arabinose 5-phosphate (A5P) and phosphoenol, pyruvate (PEP) to obtain 3-deoxy-D-manno-2-octulosonate-8-phosphate, (KDO8P). We have elucidated initial modes of ligand binding in KDO8PS, binary complexes by X-ray crystallography. Structures of the apo-enzyme, and of binary complexes with the substrate PEP, the product KDO8P and the, catalytically inactive 1-deoxy analog of arabinose 5-phosphate (1dA5P), were obtained. The KDO8PS active site resembles an irregular funnel with, positive electrostatic potential situated at the bottom of the PEP-binding, sub-site, which is the primary attractive force towards negatively charged, phosphate moieties of all ligands. The structures of the ligand-free, apo-KDO8PS and the binary complex with the product KDO8P visualize for the, first time the role of His202 as an active-site gate. Examination of the, crystal structures of KDO8PS with the KDO8P or 1dA5P shows these ligands, bound to the enzyme in the PEP-binding sub-site, and not as expected to, the A5P sub-site. Taken together, the structures presented here strengthen, earlier evidence that this enzyme functions predominantly through, positional catalysis, map out the roles of active-site residues and, provide evidence that explains the total lack of catalytic reversibility.

The enzyme 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS) catalyses the condensation of arabinose 5-phosphate (A5P) and phosphoenol pyruvate (PEP) to obtain 3-deoxy-D-manno-2-octulosonate-8-phosphate (KDO8P). We have elucidated initial modes of ligand binding in KDO8PS binary complexes by X-ray crystallography. Structures of the apo-enzyme and of binary complexes with the substrate PEP, the product KDO8P and the catalytically inactive 1-deoxy analog of arabinose 5-phosphate (1dA5P) were obtained. The KDO8PS active site resembles an irregular funnel with positive electrostatic potential situated at the bottom of the PEP-binding sub-site, which is the primary attractive force towards negatively charged phosphate moieties of all ligands. The structures of the ligand-free apo-KDO8PS and the binary complex with the product KDO8P visualize for the first time the role of His202 as an active-site gate. Examination of the crystal structures of KDO8PS with the KDO8P or 1dA5P shows these ligands bound to the enzyme in the PEP-binding sub-site, and not as expected to the A5P sub-site. Taken together, the structures presented here strengthen earlier evidence that this enzyme functions predominantly through positional catalysis, map out the roles of active-site residues and provide evidence that explains the total lack of catalytic reversibility.

==About this Structure==

1PHW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ROB as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-deoxy-8-phosphooctulonate_synthase 3-deoxy-8-phosphooctulonate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.55 2.5.1.55] Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1PHW OCA].

1PHW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ROB:'>ROB</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-deoxy-8-phosphooctulonate_synthase 3-deoxy-8-phosphooctulonate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.55 2.5.1.55] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PHW OCA].

==Reference==

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[[Category: lyase]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20 23~~:49:~~46 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:28:56 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1phw.gif|left|200px]]<br /><applet load="1phw" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1phw.gif|left|200px]]<br /><applet load="1phw" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1phw, resolution 2.36&Aring;" />
 '''Crystal structure of KDO8P synthase in its binary complex with substrate analog 1-deoxy-A5P'''<br />
 ==Overview==
-The enzyme 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS), catalyses the condensation of arabinose 5-phosphate (A5P) and phosphoenol, pyruvate (PEP) to obtain 3-deoxy-D-manno-2-octulosonate-8-phosphate, (KDO8P). We have elucidated initial modes of ligand binding in KDO8PS, binary complexes by X-ray crystallography. Structures of the apo-enzyme, and of binary complexes with the substrate PEP, the product KDO8P and the, catalytically inactive 1-deoxy analog of arabinose 5-phosphate (1dA5P), were obtained. The KDO8PS active site resembles an irregular funnel with, positive electrostatic potential situated at the bottom of the PEP-binding, sub-site, which is the primary attractive force towards negatively charged, phosphate moieties of all ligands. The structures of the ligand-free, apo-KDO8PS and the binary complex with the product KDO8P visualize for the, first time the role of His202 as an active-site gate. Examination of the, crystal structures of KDO8PS with the KDO8P or 1dA5P shows these ligands, bound to the enzyme in the PEP-binding sub-site, and not as expected to, the A5P sub-site. Taken together, the structures presented here strengthen, earlier evidence that this enzyme functions predominantly through, positional catalysis, map out the roles of active-site residues and, provide evidence that explains the total lack of catalytic reversibility.
+The enzyme 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDO8PS) catalyses the condensation of arabinose 5-phosphate (A5P) and phosphoenol pyruvate (PEP) to obtain 3-deoxy-D-manno-2-octulosonate-8-phosphate (KDO8P). We have elucidated initial modes of ligand binding in KDO8PS binary complexes by X-ray crystallography. Structures of the apo-enzyme and of binary complexes with the substrate PEP, the product KDO8P and the catalytically inactive 1-deoxy analog of arabinose 5-phosphate (1dA5P) were obtained. The KDO8PS active site resembles an irregular funnel with positive electrostatic potential situated at the bottom of the PEP-binding sub-site, which is the primary attractive force towards negatively charged phosphate moieties of all ligands. The structures of the ligand-free apo-KDO8PS and the binary complex with the product KDO8P visualize for the first time the role of His202 as an active-site gate. Examination of the crystal structures of KDO8PS with the KDO8P or 1dA5P shows these ligands bound to the enzyme in the PEP-binding sub-site, and not as expected to the A5P sub-site. Taken together, the structures presented here strengthen earlier evidence that this enzyme functions predominantly through positional catalysis, map out the roles of active-site residues and provide evidence that explains the total lack of catalytic reversibility.
 ==About this Structure==
-PHW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ROB as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-deoxy-8-phosphooctulonate_synthase 3-deoxy-8-phosphooctulonate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.55 2.5.1.55] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1PHW OCA].
+PHW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ROB:'>ROB</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/3-deoxy-8-phosphooctulonate_synthase 3-deoxy-8-phosphooctulonate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.55 2.5.1.55] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PHW OCA].
 ==Reference==
@@ Line 25: / Line 25: @@
 [[Category: lyase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 23:49:46 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:28:56 2008''