1qwj
From Proteopedia
(New page: 200px<br /><applet load="1qwj" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qwj, resolution 2.8Å" /> '''The Crystal Structure...) |
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| - | [[Image:1qwj.gif|left|200px]]<br /><applet load="1qwj" size=" | + | [[Image:1qwj.gif|left|200px]]<br /><applet load="1qwj" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qwj, resolution 2.8Å" /> | caption="1qwj, resolution 2.8Å" /> | ||
'''The Crystal Structure of Murine CMP-5-N-Acetylneuraminic Acid Synthetase'''<br /> | '''The Crystal Structure of Murine CMP-5-N-Acetylneuraminic Acid Synthetase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase | + | Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides. Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product. In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed. In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis. Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme. In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation. |
==About this Structure== | ==About this Structure== | ||
| - | 1QWJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with NCC as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/N-acylneuraminate_cytidylyltransferase N-acylneuraminate cytidylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.43 2.7.7.43] Full crystallographic information is available from [http:// | + | 1QWJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] with <scene name='pdbligand=NCC:'>NCC</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/N-acylneuraminate_cytidylyltransferase N-acylneuraminate cytidylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.43 2.7.7.43] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QWJ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Huber, R.]] | [[Category: Huber, R.]] | ||
[[Category: Jacob, U.]] | [[Category: Jacob, U.]] | ||
| - | [[Category: Kaiser, J | + | [[Category: Kaiser, J T.]] |
[[Category: Krapp, S.]] | [[Category: Krapp, S.]] | ||
| - | [[Category: Muenster-Kuehnel, A | + | [[Category: Muenster-Kuehnel, A K.]] |
[[Category: Tiralongo, J.]] | [[Category: Tiralongo, J.]] | ||
[[Category: NCC]] | [[Category: NCC]] | ||
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[[Category: sugar-activating enzyme]] | [[Category: sugar-activating enzyme]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:27 2008'' |
Revision as of 12:44, 21 February 2008
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The Crystal Structure of Murine CMP-5-N-Acetylneuraminic Acid Synthetase
Overview
Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides. Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product. In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed. In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis. Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme. In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation.
About this Structure
1QWJ is a Single protein structure of sequence from Mus musculus with as ligand. Active as N-acylneuraminate cytidylyltransferase, with EC number 2.7.7.43 Full crystallographic information is available from OCA.
Reference
The crystal structure of murine CMP-5-N-acetylneuraminic acid synthetase., Krapp S, Munster-Kuhnel AK, Kaiser JT, Huber R, Tiralongo J, Gerardy-Schahn R, Jacob U, J Mol Biol. 2003 Dec 5;334(4):625-37. PMID:14636592
Page seeded by OCA on Thu Feb 21 14:44:27 2008
Categories: Mus musculus | N-acylneuraminate cytidylyltransferase | Single protein | Gerardy-Schahn, R. | Huber, R. | Jacob, U. | Kaiser, J T. | Krapp, S. | Muenster-Kuehnel, A K. | Tiralongo, J. | NCC | Cmp-5-n-acetylneuraminic acid synthetase | Cmp-neu5ac | Glycosylation | Lipopolysaccharide biosynthesis | Sialic acid | Sugar-activating enzyme
