2vk5
From Proteopedia
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[[Image:2vk5.jpg|left|200px]] | [[Image:2vk5.jpg|left|200px]] | ||
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| - | | | + | {{STRUCTURE_2vk5| PDB=2vk5 | SCENE= }} |
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'''THE STRUCTURE OF CLOSTRIDIUM PERFRINGENS NANI SIALIDASE AND ITS CATALYTIC INTERMEDIATES''' | '''THE STRUCTURE OF CLOSTRIDIUM PERFRINGENS NANI SIALIDASE AND ITS CATALYTIC INTERMEDIATES''' | ||
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| + | ==Overview== | ||
| + | Clostridium perfringens is a Gram-positive bacterium responsible for bacteremia, gas gangrene, and occasionally food poisoning. Its genome encodes three sialidases, nanH, nanI, and nanJ, that are involved in the removal of sialic acids from a variety of glycoconjugates and that play a role in bacterial nutrition and pathogenesis. Recent studies on trypanosomal (trans-) sialidases have suggested that catalysis in all sialidases may proceed via a covalent intermediate similar to that of other retaining glycosidases. Here we provide further evidence to support this suggestion by reporting the 0.97A resolution atomic structure of the catalytic domain of the C. perfringens NanI sialidase, and complexes with its substrate sialic acid (N-acetylneuramic acid) also to 0.97A resolution, with a transition-state analogue (2-deoxy-2,3-dehydro-N-acetylneuraminic acid) to 1.5A resolution, and with a covalent intermediate formed using a fluorinated sialic acid analogue to 1.2A resolution. Together, these structures provide high resolution snapshots along the catalytic pathway. The crystal structures suggested that NanI is able to hydrate 2-deoxy-2,3-dehydro-N-acetylneuraminic acid to N-acetylneuramic acid. This was confirmed by NMR, and a mechanism for this activity is suggested. | ||
==About this Structure== | ==About this Structure== | ||
2VK5 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_perfringens Clostridium perfringens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VK5 OCA]. | 2VK5 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Clostridium_perfringens Clostridium perfringens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VK5 OCA]. | ||
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| + | ==Reference== | ||
| + | The Structure of Clostridium perfringens NanI Sialidase and Its Catalytic Intermediates., Newstead SL, Potter JA, Wilson JC, Xu G, Chien CH, Watts AG, Withers SG, Taylor GL, J Biol Chem. 2008 Apr 4;283(14):9080-8. Epub 2008 Jan 24. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/18218621 18218621] | ||
[[Category: Clostridium perfringens]] | [[Category: Clostridium perfringens]] | ||
[[Category: Exo-alpha-sialidase]] | [[Category: Exo-alpha-sialidase]] | ||
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[[Category: Withers, S G.]] | [[Category: Withers, S G.]] | ||
[[Category: Xu, G.]] | [[Category: Xu, G.]] | ||
| - | [[Category: | + | [[Category: Clostridium perfringen]] |
| - | [[Category: | + | [[Category: Glycosidase]] |
| - | [[Category: | + | [[Category: Hydrolase]] |
| - | [[Category: | + | [[Category: Sialic acid]] |
| - | [[Category: | + | [[Category: Sialidase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Apr 9 14:42:27 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 11:42, 9 April 2008
THE STRUCTURE OF CLOSTRIDIUM PERFRINGENS NANI SIALIDASE AND ITS CATALYTIC INTERMEDIATES
Overview
Clostridium perfringens is a Gram-positive bacterium responsible for bacteremia, gas gangrene, and occasionally food poisoning. Its genome encodes three sialidases, nanH, nanI, and nanJ, that are involved in the removal of sialic acids from a variety of glycoconjugates and that play a role in bacterial nutrition and pathogenesis. Recent studies on trypanosomal (trans-) sialidases have suggested that catalysis in all sialidases may proceed via a covalent intermediate similar to that of other retaining glycosidases. Here we provide further evidence to support this suggestion by reporting the 0.97A resolution atomic structure of the catalytic domain of the C. perfringens NanI sialidase, and complexes with its substrate sialic acid (N-acetylneuramic acid) also to 0.97A resolution, with a transition-state analogue (2-deoxy-2,3-dehydro-N-acetylneuraminic acid) to 1.5A resolution, and with a covalent intermediate formed using a fluorinated sialic acid analogue to 1.2A resolution. Together, these structures provide high resolution snapshots along the catalytic pathway. The crystal structures suggested that NanI is able to hydrate 2-deoxy-2,3-dehydro-N-acetylneuraminic acid to N-acetylneuramic acid. This was confirmed by NMR, and a mechanism for this activity is suggested.
About this Structure
2VK5 is a Single protein structure of sequence from Clostridium perfringens. Full crystallographic information is available from OCA.
Reference
The Structure of Clostridium perfringens NanI Sialidase and Its Catalytic Intermediates., Newstead SL, Potter JA, Wilson JC, Xu G, Chien CH, Watts AG, Withers SG, Taylor GL, J Biol Chem. 2008 Apr 4;283(14):9080-8. Epub 2008 Jan 24. PMID:18218621 Page seeded by OCA on Wed Apr 9 14:42:27 2008
