1xge: Difference between revisions
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[[Image:1xge.gif|left|200px]] | [[Image:1xge.gif|left|200px]] | ||
'''Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits''' | {{Structure | ||
|PDB= 1xge |SIZE=350|CAPTION= <scene name='initialview01'>1xge</scene>, resolution 1.90Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene>, <scene name='pdbligand=DOR:(4S)-2,6-DIOXOHEXAHYDROPYRIMIDINE-4-CARBOXYLIC+ACID'>DOR</scene> and <scene name='pdbligand=NCD:N-CARBAMOYL-L-ASPARTATE'>NCD</scene> | |||
|ACTIVITY= [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] | |||
|GENE= pyrC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1XGE is a [ | 1XGE is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XGE OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/15826651 15826651] | ||
[[Category: Dihydroorotase]] | [[Category: Dihydroorotase]] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
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[[Category: tim barrel]] | [[Category: tim barrel]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:09:27 2008'' | ||
Revision as of 13:09, 20 March 2008
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| 1xge, resolution 1.90Å | |||||||||||||
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| Ligands: | ZN, DOR and NCD | ||||||||||||
| Gene: | pyrC (Escherichia coli) | ||||||||||||
| Activity: | Dihydroorotase, with EC number 3.5.2.3 | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
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. 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
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