2g3m
From Proteopedia
(New page: 200px<br /><applet load="2g3m" size="450" color="white" frame="true" align="right" spinBox="true" caption="2g3m, resolution 2.55Å" /> '''Crystal structure of...) |
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| - | [[Image:2g3m.gif|left|200px]]<br /><applet load="2g3m" size=" | + | [[Image:2g3m.gif|left|200px]]<br /><applet load="2g3m" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2g3m, resolution 2.55Å" /> | caption="2g3m, resolution 2.55Å" /> | ||
'''Crystal structure of the Sulfolobus solfataricus alpha-glucosidase MalA'''<br /> | '''Crystal structure of the Sulfolobus solfataricus alpha-glucosidase MalA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of alpha-glucosidase MalA from Sulfolobus | + | The crystal structure of alpha-glucosidase MalA from Sulfolobus solfataricus has been determined at 2.5Angstrom resolution. It provides a structural model for enzymes representing the major specificity in glycoside hydrolase family 31 (GH31), including alpha-glucosidases from higher organisms, involved in glycogen degradation and glycoprotein processing. The structure of MalA shows clear differences from the only other structure known from GH31, alpha-xylosidase YicI. MalA and YicI share only 23% sequence identity. Although the two enzymes display a similar domain structure and both form hexamers, their structures differ significantly in quaternary organization: MalA is a dimer of trimers, YicI a trimer of dimers. MalA and YicI also differ in their substrate specificities, as shown by kinetic measurements on model chromogenic substrates. In addition, MalA has a clear preference for maltose (Glc-alpha1,4-Glc), whereas YicI prefers isoprimeverose (Xyl-alpha1,6-Glc). The structural origin of this difference occurs in the -1 subsite where MalA residues Asp251 and Trp284 could interact with OH6 of the substrate. The structure of MalA in complex with beta-octyl-glucopyranoside has been determined. It reveals Arg400, Asp87, Trp284, Met321 and Phe327 as invariant residues forming the +1 subsite in the GH31 alpha-glucosidases. Structural comparisons with other GH families suggest that the GH31 enzymes belong to clan GH-D. |
==About this Structure== | ==About this Structure== | ||
| - | 2G3M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus]. Active as [http://en.wikipedia.org/wiki/Alpha-glucosidase Alpha-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.20 3.2.1.20] Full crystallographic information is available from [http:// | + | 2G3M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus]. Active as [http://en.wikipedia.org/wiki/Alpha-glucosidase Alpha-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.20 3.2.1.20] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G3M OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Sulfolobus solfataricus]] | [[Category: Sulfolobus solfataricus]] | ||
[[Category: Blum, P.]] | [[Category: Blum, P.]] | ||
| - | [[Category: Ernst, H | + | [[Category: Ernst, H A.]] |
[[Category: Larsen, S.]] | [[Category: Larsen, S.]] | ||
| - | [[Category: Leggio, L | + | [[Category: Leggio, L Lo.]] |
[[Category: Leonard, G.]] | [[Category: Leonard, G.]] | ||
[[Category: Willemoes, M.]] | [[Category: Willemoes, M.]] | ||
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[[Category: retaining mechanism]] | [[Category: retaining mechanism]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:27:50 2008'' |
Revision as of 15:27, 21 February 2008
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Crystal structure of the Sulfolobus solfataricus alpha-glucosidase MalA
Overview
The crystal structure of alpha-glucosidase MalA from Sulfolobus solfataricus has been determined at 2.5Angstrom resolution. It provides a structural model for enzymes representing the major specificity in glycoside hydrolase family 31 (GH31), including alpha-glucosidases from higher organisms, involved in glycogen degradation and glycoprotein processing. The structure of MalA shows clear differences from the only other structure known from GH31, alpha-xylosidase YicI. MalA and YicI share only 23% sequence identity. Although the two enzymes display a similar domain structure and both form hexamers, their structures differ significantly in quaternary organization: MalA is a dimer of trimers, YicI a trimer of dimers. MalA and YicI also differ in their substrate specificities, as shown by kinetic measurements on model chromogenic substrates. In addition, MalA has a clear preference for maltose (Glc-alpha1,4-Glc), whereas YicI prefers isoprimeverose (Xyl-alpha1,6-Glc). The structural origin of this difference occurs in the -1 subsite where MalA residues Asp251 and Trp284 could interact with OH6 of the substrate. The structure of MalA in complex with beta-octyl-glucopyranoside has been determined. It reveals Arg400, Asp87, Trp284, Met321 and Phe327 as invariant residues forming the +1 subsite in the GH31 alpha-glucosidases. Structural comparisons with other GH families suggest that the GH31 enzymes belong to clan GH-D.
About this Structure
2G3M is a Single protein structure of sequence from Sulfolobus solfataricus. Active as Alpha-glucosidase, with EC number 3.2.1.20 Full crystallographic information is available from OCA.
Reference
Structure of the Sulfolobus solfataricus alpha-glucosidase: implications for domain conservation and substrate recognition in GH31., Ernst HA, Lo Leggio L, Willemoes M, Leonard G, Blum P, Larsen S, J Mol Biol. 2006 May 12;358(4):1106-24. Epub 2006 Mar 13. PMID:16580018
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