2owc
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Amylomaltases are glycosyl hydrolases belonging to glycoside hydrolase | + | Amylomaltases are glycosyl hydrolases belonging to glycoside hydrolase family 77 that are capable of the synthesis of large cyclic glucans and the disproportionation of oligosaccharides. Using protein crystallography, we have generated a flip book movie of the amylomaltase catalytic cycle in atomic detail. The structures include a covalent glycosyl enzyme intermediate and a covalent intermediate in complex with an analogue of a co-substrate and show how the structures of both enzyme and substrate respond to the changes required by the catalytic cycle as it proceeds. Notably, the catalytic nucleophile changes conformation dramatically during the reaction. Also, Gln-256 on the 250s loop is involved in orienting the substrate in the +1 site. The absence of a suitable base in the covalent intermediate structure explains the low hydrolysis activity. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Three-way stabilization of the covalent intermediate in amylomaltase, an alpha-amylase-like transglycosylase., Barends TR, Bultema JB, Kaper T, van der Maarel MJ, Dijkhuizen L, Dijkstra BW, J Biol Chem. 2007 Apr 9 | + | Three-way stabilization of the covalent intermediate in amylomaltase, an alpha-amylase-like transglycosylase., Barends TR, Bultema JB, Kaper T, van der Maarel MJ, Dijkhuizen L, Dijkstra BW, J Biol Chem. 2007 Jun 8;282(23):17242-9. Epub 2007 Apr 9. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17420245 17420245] |
[[Category: 4-alpha-glucanotransferase]] | [[Category: 4-alpha-glucanotransferase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Thermus thermophilus]] | [[Category: Thermus thermophilus]] | ||
| - | [[Category: Barends, T | + | [[Category: Barends, T R.M.]] |
| - | [[Category: Bultema, J | + | [[Category: Bultema, J B.]] |
[[Category: Dijkhuizen, L.]] | [[Category: Dijkhuizen, L.]] | ||
| - | [[Category: Dijkstra, B | + | [[Category: Dijkstra, B W.]] |
[[Category: Kaper, T.]] | [[Category: Kaper, T.]] | ||
| - | [[Category: Maarel, M | + | [[Category: Maarel, M J.E C.van der.]] |
[[Category: ACR]] | [[Category: ACR]] | ||
[[Category: GOL]] | [[Category: GOL]] | ||
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[[Category: glycosyl-enzyme]] | [[Category: glycosyl-enzyme]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:23:17 2008'' |
Revision as of 16:23, 21 February 2008
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Structure of a covalent intermediate in Thermus thermophilus amylomaltase
Overview
Amylomaltases are glycosyl hydrolases belonging to glycoside hydrolase family 77 that are capable of the synthesis of large cyclic glucans and the disproportionation of oligosaccharides. Using protein crystallography, we have generated a flip book movie of the amylomaltase catalytic cycle in atomic detail. The structures include a covalent glycosyl enzyme intermediate and a covalent intermediate in complex with an analogue of a co-substrate and show how the structures of both enzyme and substrate respond to the changes required by the catalytic cycle as it proceeds. Notably, the catalytic nucleophile changes conformation dramatically during the reaction. Also, Gln-256 on the 250s loop is involved in orienting the substrate in the +1 site. The absence of a suitable base in the covalent intermediate structure explains the low hydrolysis activity.
About this Structure
2OWC is a Single protein structure of sequence from Thermus thermophilus with , and as ligands. Active as 4-alpha-glucanotransferase, with EC number 2.4.1.25 Full crystallographic information is available from OCA.
Reference
Three-way stabilization of the covalent intermediate in amylomaltase, an alpha-amylase-like transglycosylase., Barends TR, Bultema JB, Kaper T, van der Maarel MJ, Dijkhuizen L, Dijkstra BW, J Biol Chem. 2007 Jun 8;282(23):17242-9. Epub 2007 Apr 9. PMID:17420245
Page seeded by OCA on Thu Feb 21 18:23:17 2008
