1xge
From Proteopedia
(New page: 200px<br /><applet load="1xge" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xge, resolution 1.90Å" /> '''Dihydroorotase from ...) |
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| - | [[Image:1xge.gif|left|200px]]<br /><applet load="1xge" size=" | + | [[Image:1xge.gif|left|200px]]<br /><applet load="1xge" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1xge, resolution 1.90Å" /> | caption="1xge, resolution 1.90Å" /> | ||
'''Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits'''<br /> | '''Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Escherichia coli dihydroorotase has been crystallized in the presence of | + | 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== | ==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:// | + | 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== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chan, C | + | [[Category: Chan, C W.]] |
| - | [[Category: Christopherson, R | + | [[Category: Christopherson, R I.]] |
| - | [[Category: Guss, J | + | [[Category: Guss, J M.]] |
[[Category: Lee, M.]] | [[Category: Lee, M.]] | ||
| - | [[Category: Maher, M | + | [[Category: Maher, M J.]] |
[[Category: DOR]] | [[Category: DOR]] | ||
[[Category: NCD]] | [[Category: NCD]] | ||
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[[Category: tim barrel]] | [[Category: tim barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:54:33 2008'' |
Revision as of 13:54, 21 February 2008
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Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits
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.
About this Structure
1XGE is a Single protein structure of sequence from Escherichia coli with , and as ligands. Active as Dihydroorotase, with EC number 3.5.2.3 Full crystallographic information is available from OCA.
Reference
Dihydroorotase from Escherichia coli: loop movement and cooperativity between subunits., Lee M, Chan CW, Mitchell Guss J, Christopherson RI, Maher MJ, J Mol Biol. 2005 May 6;348(3):523-33. PMID:15826651
Page seeded by OCA on Thu Feb 21 15:54:33 2008
Categories: Dihydroorotase | Escherichia coli | Single protein | Chan, C W. | Christopherson, R I. | Guss, J M. | Lee, M. | Maher, M J. | DOR | NCD | ZN | Tim barrel
