1xge: Difference between revisions

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

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

caption="1xge, resolution 1.90Å" />

'''Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits'''<br />

==Overview==

Escherichia coli dihydroorotase has been crystallized in the presence of, the product, L-dihydroorotate (L-DHO), and the structure refined at 1.9A, resolution. The structure confirms that previously reported (PDB entry, 1J79), crystallized in the presence of the substrate, N-carbamyl-D,L-aspartate (D, L-CA-asp), which had a dimer in the, asymmetric unit, with one subunit having the substrate, L-CA-asp bound at, the active site and the other having L-DHO. Importantly, no explanation, for the unusual structure was given. Our results now show that a loop, comprised of residues 105-115 has different conformations in the two, subunits. In the case of the L-CA-asp-bound subunit, this loop reaches in, toward the active site and makes hydrogen-bonding contact with the bound, substrate molecule. For the L-DHO-bound subunit, the loop faces in the, opposite direction and forms part of the surface of the protein. Analysis, of the kinetics for conversion of L-DHO to L-CA-asp at low concentrations, of L-DHO shows positive cooperativity with a Hill coefficient, n=1.57(+/-0.13). Communication between subunits in the dimer may occur via, cooperative conformational changes of the side-chains of a tripeptide from, each subunit: Arg256-His257-Arg258, near the subunit interface.

Escherichia coli dihydroorotase has been crystallized in the presence of the product, L-dihydroorotate (L-DHO), and the structure refined at 1.9A resolution. The structure confirms that previously reported (PDB entry 1J79), crystallized in the presence of the substrate N-carbamyl-D,L-aspartate (D, L-CA-asp), which had a dimer in the asymmetric unit, with one subunit having the substrate, L-CA-asp bound at the active site and the other having L-DHO. Importantly, no explanation for the unusual structure was given. Our results now show that a loop comprised of residues 105-115 has different conformations in the two subunits. In the case of the L-CA-asp-bound subunit, this loop reaches in toward the active site and makes hydrogen-bonding contact with the bound substrate molecule. For the L-DHO-bound subunit, the loop faces in the opposite direction and forms part of the surface of the protein. Analysis of the kinetics for conversion of L-DHO to L-CA-asp at low concentrations of L-DHO shows positive cooperativity with a Hill coefficient n=1.57(+/-0.13). Communication between subunits in the dimer may occur via cooperative conformational changes of the side-chains of a tripeptide from each subunit: Arg256-His257-Arg258, near the subunit interface.

==About this Structure==

1XGE 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 ZN, DOR and NCD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Dihydroorotase Dihydroorotase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.3 3.5.2.3] Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1XGE OCA].

1XGE 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=ZN:'>ZN</scene>, <scene name='pdbligand=DOR:'>DOR</scene> and <scene name='pdbligand=NCD:'>NCD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Dihydroorotase Dihydroorotase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.3 3.5.2.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XGE OCA].

==Reference==

Line 14:

[[Category: Escherichia coli]]

[[Category: Single protein]]

[[Category: Chan, C.W.]]

[[Category: Chan, C W.]]

[[Category: Christopherson, R.I.]]

[[Category: Christopherson, R I.]]

[[Category: Guss, J.M.]]

[[Category: Guss, J M.]]

[[Category: Lee, M.]]

[[Category: Maher, M.J.]]

[[Category: Maher, M J.]]

[[Category: DOR]]

[[Category: NCD]]

Line 24:

[[Category: tim barrel]]

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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:54:33 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1xge.gif|left|200px]]<br /><applet load="1xge" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1xge.gif|left|200px]]<br /><applet load="1xge" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1xge, resolution 1.90&Aring;" />
 '''Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits'''<br />
 ==Overview==
-Escherichia coli dihydroorotase has been crystallized in the presence of, the product, L-dihydroorotate (L-DHO), and the structure refined at 1.9A, resolution. The structure confirms that previously reported (PDB entry, 1J79), crystallized in the presence of the substrate, N-carbamyl-D,L-aspartate (D, L-CA-asp), which had a dimer in the, asymmetric unit, with one subunit having the substrate, L-CA-asp bound at, the active site and the other having L-DHO. Importantly, no explanation, for the unusual structure was given. Our results now show that a loop, comprised of residues 105-115 has different conformations in the two, subunits. In the case of the L-CA-asp-bound subunit, this loop reaches in, toward the active site and makes hydrogen-bonding contact with the bound, substrate molecule. For the L-DHO-bound subunit, the loop faces in the, opposite direction and forms part of the surface of the protein. Analysis, of the kinetics for conversion of L-DHO to L-CA-asp at low concentrations, of L-DHO shows positive cooperativity with a Hill coefficient, n=1.57(+/-0.13). Communication between subunits in the dimer may occur via, cooperative conformational changes of the side-chains of a tripeptide from, each subunit: Arg256-His257-Arg258, near the subunit interface.
+Escherichia coli dihydroorotase has been crystallized in the presence of the product, L-dihydroorotate (L-DHO), and the structure refined at 1.9A resolution. The structure confirms that previously reported (PDB entry 1J79), crystallized in the presence of the substrate N-carbamyl-D,L-aspartate (D, L-CA-asp), which had a dimer in the asymmetric unit, with one subunit having the substrate, L-CA-asp bound at the active site and the other having L-DHO. Importantly, no explanation for the unusual structure was given. Our results now show that a loop comprised of residues 105-115 has different conformations in the two subunits. In the case of the L-CA-asp-bound subunit, this loop reaches in toward the active site and makes hydrogen-bonding contact with the bound substrate molecule. For the L-DHO-bound subunit, the loop faces in the opposite direction and forms part of the surface of the protein. Analysis of the kinetics for conversion of L-DHO to L-CA-asp at low concentrations of L-DHO shows positive cooperativity with a Hill coefficient n=1.57(+/-0.13). Communication between subunits in the dimer may occur via cooperative conformational changes of the side-chains of a tripeptide from each subunit: Arg256-His257-Arg258, near the subunit interface.
 ==About this Structure==
-XGE 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 ZN, DOR and NCD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Dihydroorotase Dihydroorotase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.3 3.5.2.3] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1XGE OCA].
+XGE 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=ZN:'>ZN</scene>, <scene name='pdbligand=DOR:'>DOR</scene> and <scene name='pdbligand=NCD:'>NCD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Dihydroorotase Dihydroorotase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.3 3.5.2.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XGE OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Escherichia coli]]
 [[Category: Single protein]]
-[[Category: Chan, C.W.]]
+[[Category: Chan, C W.]]
-[[Category: Christopherson, R.I.]]
+[[Category: Christopherson, R I.]]
-[[Category: Guss, J.M.]]
+[[Category: Guss, J M.]]
 [[Category: Lee, M.]]
-[[Category: Maher, M.J.]]
+[[Category: Maher, M J.]]
 [[Category: DOR]]
 [[Category: NCD]]
@@ Line 24: / Line 24: @@
 [[Category: tim barrel]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 06:03:46 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:54:33 2008''