4sli
From Proteopedia
(New page: 200px<br /><applet load="4sli" size="450" color="white" frame="true" align="right" spinBox="true" caption="4sli, resolution 1.8Å" /> '''LEECH INTRAMOLECULAR ...) |
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| - | [[Image:4sli.jpg|left|200px]]<br /><applet load="4sli" size=" | + | [[Image:4sli.jpg|left|200px]]<br /><applet load="4sli" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="4sli, resolution 1.8Å" /> | caption="4sli, resolution 1.8Å" /> | ||
'''LEECH INTRAMOLECULAR TRANS-SIALIDASE COMPLEXED WITH 2-PROPENYL-NEU5AC, AN INACTIVE SUBSTRATE ANALOGUE'''<br /> | '''LEECH INTRAMOLECULAR TRANS-SIALIDASE COMPLEXED WITH 2-PROPENYL-NEU5AC, AN INACTIVE SUBSTRATE ANALOGUE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Intramolecular trans-sialidase from leech (Macrobdella decora) is the | + | Intramolecular trans-sialidase from leech (Macrobdella decora) is the first member of the sialidase superfamily found to exhibit strict specificity towards the cleavage of terminal Neu5Acalpha2-->3Gal linkage in sialoglycoconjugates. Its release of 2,7-anhydro-Neu5Ac instead of Neu5Ac indicates that it catalyzes an intramolecular trans-sialosyl reaction. Crystal structures of its complexes with an inactive substrate analogue 2-propenyl-Neu5Ac, and with the product 2,7-anhydro-Neu5Ac, have been determined to 1.8 A resolution. The boat conformation of the pyranose observed in the complexes supports the proposed enzymatic mechanism that O7 of an axial 6-glycerol group attacks the positively charged C2 of the intermediate. A generalized mechanism is proposed for the sialidase superfamily. |
==About this Structure== | ==About this Structure== | ||
| - | 4SLI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Macrobdella_decora Macrobdella decora] with CNP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Exo-alpha-sialidase Exo-alpha-sialidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.18 3.2.1.18] Full crystallographic information is available from [http:// | + | 4SLI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Macrobdella_decora Macrobdella decora] with <scene name='pdbligand=CNP:'>CNP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Exo-alpha-sialidase Exo-alpha-sialidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.18 3.2.1.18] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4SLI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Macrobdella decora]] | [[Category: Macrobdella decora]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Li, S | + | [[Category: Li, S C.]] |
| - | [[Category: Li, Y | + | [[Category: Li, Y T.]] |
[[Category: Luo, M.]] | [[Category: Luo, M.]] | ||
[[Category: Luo, Y.]] | [[Category: Luo, Y.]] | ||
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[[Category: intramolecular trans-sialidase]] | [[Category: intramolecular trans-sialidase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:14:24 2008'' |
Revision as of 17:14, 21 February 2008
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LEECH INTRAMOLECULAR TRANS-SIALIDASE COMPLEXED WITH 2-PROPENYL-NEU5AC, AN INACTIVE SUBSTRATE ANALOGUE
Overview
Intramolecular trans-sialidase from leech (Macrobdella decora) is the first member of the sialidase superfamily found to exhibit strict specificity towards the cleavage of terminal Neu5Acalpha2-->3Gal linkage in sialoglycoconjugates. Its release of 2,7-anhydro-Neu5Ac instead of Neu5Ac indicates that it catalyzes an intramolecular trans-sialosyl reaction. Crystal structures of its complexes with an inactive substrate analogue 2-propenyl-Neu5Ac, and with the product 2,7-anhydro-Neu5Ac, have been determined to 1.8 A resolution. The boat conformation of the pyranose observed in the complexes supports the proposed enzymatic mechanism that O7 of an axial 6-glycerol group attacks the positively charged C2 of the intermediate. A generalized mechanism is proposed for the sialidase superfamily.
About this Structure
4SLI is a Single protein structure of sequence from Macrobdella decora with as ligand. Active as Exo-alpha-sialidase, with EC number 3.2.1.18 Full crystallographic information is available from OCA.
Reference
The 1.8 A structures of leech intramolecular trans-sialidase complexes: evidence of its enzymatic mechanism., Luo Y, Li SC, Li YT, Luo M, J Mol Biol. 1999 Jan 8;285(1):323-32. PMID:9878409
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