2a0f
From Proteopedia
(New page: 200px<br /><applet load="2a0f" size="450" color="white" frame="true" align="right" spinBox="true" caption="2a0f, resolution 2.9Å" /> '''Structure of D236A mu...) |
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| - | [[Image:2a0f.gif|left|200px]]<br /><applet load="2a0f" size=" | + | [[Image:2a0f.gif|left|200px]]<br /><applet load="2a0f" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2a0f, resolution 2.9Å" /> | caption="2a0f, resolution 2.9Å" /> | ||
'''Structure of D236A mutant E. coli Aspartate Transcarbamoylase in presence of Phosphonoacetamide at 2.90 A resolution'''<br /> | '''Structure of D236A mutant E. coli Aspartate Transcarbamoylase in presence of Phosphonoacetamide at 2.90 A resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Snapshots of the catalytic cycle of the allosteric enzyme aspartate | + | Snapshots of the catalytic cycle of the allosteric enzyme aspartate transcarbamoylase have been obtained via X-ray crystallography. The enzyme in the high-activity high-affinity R state contains two catalytic chains in the asymmetric unit that are different. The active site in one chain is empty, while the active site in the other chain contains an analog of the first substrate to bind in the ordered mechanism of the reaction. Small angle X-ray scattering shows that once the enzyme is converted to the R state, by substrate binding, the enzyme remains in the R state until substrates are exhausted. Thus, this structure represents the active form of the enzyme trapped at two different stages in the catalytic cycle, before the substrates bind (or after the products are released), and after the first substrate binds. Opening and closing of the catalytic chain domains explains how the catalytic cycle occurs while the enzyme remains globally in the R-quaternary structure. |
==About this Structure== | ==About this Structure== | ||
| - | 2A0F is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with ZN and PCT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate_carbamoyltransferase Aspartate carbamoyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.3.2 2.1.3.2] Full crystallographic information is available from [http:// | + | 2A0F is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=PCT:'>PCT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Aspartate_carbamoyltransferase Aspartate carbamoyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.3.2 2.1.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A0F OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Cardia, J | + | [[Category: Cardia, J P.]] |
| - | [[Category: Dusinberre, K | + | [[Category: Dusinberre, K J.]] |
| - | [[Category: Kantrowitz, E | + | [[Category: Kantrowitz, E R.]] |
| - | [[Category: Stieglitz, K | + | [[Category: Stieglitz, K A.]] |
[[Category: Tsuruta, H.]] | [[Category: Tsuruta, H.]] | ||
[[Category: PCT]] | [[Category: PCT]] | ||
| Line 26: | Line 26: | ||
[[Category: homotropic cooperativity]] | [[Category: homotropic cooperativity]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:22:26 2008'' |
Revision as of 14:22, 21 February 2008
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Structure of D236A mutant E. coli Aspartate Transcarbamoylase in presence of Phosphonoacetamide at 2.90 A resolution
Overview
Snapshots of the catalytic cycle of the allosteric enzyme aspartate transcarbamoylase have been obtained via X-ray crystallography. The enzyme in the high-activity high-affinity R state contains two catalytic chains in the asymmetric unit that are different. The active site in one chain is empty, while the active site in the other chain contains an analog of the first substrate to bind in the ordered mechanism of the reaction. Small angle X-ray scattering shows that once the enzyme is converted to the R state, by substrate binding, the enzyme remains in the R state until substrates are exhausted. Thus, this structure represents the active form of the enzyme trapped at two different stages in the catalytic cycle, before the substrates bind (or after the products are released), and after the first substrate binds. Opening and closing of the catalytic chain domains explains how the catalytic cycle occurs while the enzyme remains globally in the R-quaternary structure.
About this Structure
2A0F is a Protein complex structure of sequences from Escherichia coli with and as ligands. Active as Aspartate carbamoyltransferase, with EC number 2.1.3.2 Full crystallographic information is available from OCA.
Reference
Structure of the E.coli aspartate transcarbamoylase trapped in the middle of the catalytic cycle., Stieglitz KA, Dusinberre KJ, Cardia JP, Tsuruta H, Kantrowitz ER, J Mol Biol. 2005 Sep 16;352(2):478-86. PMID:16120448
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