1szn
From Proteopedia
(New page: 200px<br /><applet load="1szn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1szn, resolution 1.54Å" /> '''THE STRUCTURE OF ALP...) |
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| - | [[Image:1szn.gif|left|200px]]<br /><applet load="1szn" size=" | + | [[Image:1szn.gif|left|200px]]<br /><applet load="1szn" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1szn, resolution 1.54Å" /> | caption="1szn, resolution 1.54Å" /> | ||
'''THE STRUCTURE OF ALPHA-GALACTOSIDASE'''<br /> | '''THE STRUCTURE OF ALPHA-GALACTOSIDASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structures of alpha-galactosidase from the mesophilic fungus | + | The crystal structures of alpha-galactosidase from the mesophilic fungus Trichoderma reesei and its complex with the competitive inhibitor, beta-d-galactose, have been determined at 1.54 A and 2.0 A resolution, respectively. The alpha-galactosidase structure was solved by the quick cryo-soaking method using a single Cs derivative. The refined crystallographic model of the alpha-galactosidase consists of two domains, an N-terminal catalytic domain of the (beta/alpha)8 barrel topology and a C-terminal domain which is formed by an antiparallel beta-structure. The protein contains four N-glycosylation sites located in the catalytic domain. Some of the oligosaccharides were found to participate in inter-domain contacts. The galactose molecule binds to the active site pocket located in the center of the barrel of the catalytic domain. Analysis of the alpha-galactosidase- galactose complex reveals the residues of the active site and offers a structural basis for identification of the putative mechanism of the enzymatic reaction. The structure of the alpha-galactosidase closely resembles those of the glycoside hydrolase family 27. The conservation of two catalytic Asp residues, identified for this family, is consistent with a double-displacement reaction mechanism for the alpha-galactosidase. Modeling of possible substrates into the active site reveals specific hydrogen bonds and hydrophobic interactions that could explain peculiarities of the enzyme kinetics. |
==About this Structure== | ==About this Structure== | ||
| - | 1SZN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hypocrea_jecorina Hypocrea jecorina] with GOL as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Alpha-galactosidase Alpha-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.22 3.2.1.22] Full crystallographic information is available from [http:// | + | 1SZN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hypocrea_jecorina Hypocrea jecorina] with <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Alpha-galactosidase Alpha-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.22 3.2.1.22] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SZN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Hypocrea jecorina]] | [[Category: Hypocrea jecorina]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Eneyskaya, E | + | [[Category: Eneyskaya, E V.]] |
| - | [[Category: Golubev, A | + | [[Category: Golubev, A M.]] |
| - | [[Category: Kulminskaya, A | + | [[Category: Kulminskaya, A A.]] |
| - | [[Category: Nagem, R | + | [[Category: Nagem, R A.P.]] |
| - | [[Category: Neto, J | + | [[Category: Neto, J R.Brando.]] |
| - | [[Category: Neustroev, K | + | [[Category: Neustroev, K N.]] |
[[Category: Polikarpov, I.]] | [[Category: Polikarpov, I.]] | ||
| - | [[Category: Shabalin, K | + | [[Category: Shabalin, K A.]] |
| - | [[Category: ev, A | + | [[Category: ev, A N.Savel.]] |
[[Category: GOL]] | [[Category: GOL]] | ||
[[Category: (beta/alpha)8 barrel]] | [[Category: (beta/alpha)8 barrel]] | ||
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[[Category: two domains]] | [[Category: two domains]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:07:57 2008'' |
Revision as of 13:07, 21 February 2008
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THE STRUCTURE OF ALPHA-GALACTOSIDASE
Overview
The crystal structures of alpha-galactosidase from the mesophilic fungus Trichoderma reesei and its complex with the competitive inhibitor, beta-d-galactose, have been determined at 1.54 A and 2.0 A resolution, respectively. The alpha-galactosidase structure was solved by the quick cryo-soaking method using a single Cs derivative. The refined crystallographic model of the alpha-galactosidase consists of two domains, an N-terminal catalytic domain of the (beta/alpha)8 barrel topology and a C-terminal domain which is formed by an antiparallel beta-structure. The protein contains four N-glycosylation sites located in the catalytic domain. Some of the oligosaccharides were found to participate in inter-domain contacts. The galactose molecule binds to the active site pocket located in the center of the barrel of the catalytic domain. Analysis of the alpha-galactosidase- galactose complex reveals the residues of the active site and offers a structural basis for identification of the putative mechanism of the enzymatic reaction. The structure of the alpha-galactosidase closely resembles those of the glycoside hydrolase family 27. The conservation of two catalytic Asp residues, identified for this family, is consistent with a double-displacement reaction mechanism for the alpha-galactosidase. Modeling of possible substrates into the active site reveals specific hydrogen bonds and hydrophobic interactions that could explain peculiarities of the enzyme kinetics.
About this Structure
1SZN is a Single protein structure of sequence from Hypocrea jecorina with as ligand. Active as Alpha-galactosidase, with EC number 3.2.1.22 Full crystallographic information is available from OCA.
Reference
Crystal structure of alpha-galactosidase from Trichoderma reesei and its complex with galactose: implications for catalytic mechanism., Golubev AM, Nagem RA, Brandao Neto JR, Neustroev KN, Eneyskaya EV, Kulminskaya AA, Shabalin KA, Savel'ev AN, Polikarpov I, J Mol Biol. 2004 May 28;339(2):413-22. PMID:15136043
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