2g3n: Difference between revisions

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Crystal structure of the Sulfolobus solfataricus alpha-glucosidase MalA in complex with beta-octyl-glucopyranoside

OverviewOverview

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 StructureAbout this Structure

2G3N is a Single protein structure of sequence from Sulfolobus solfataricus with as ligand. Active as Alpha-glucosidase, with EC number 3.2.1.20 Full crystallographic information is available from OCA.

ReferenceReference

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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-[[Image:2g3n.gif|left|200px]]<br /><applet load="2g3n" size="450" color="white" frame="true" align="right" spinBox="true"
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 caption="2g3n, resolution 2.55&Aring;" />
 '''Crystal structure of the Sulfolobus solfataricus alpha-glucosidase MalA in complex with beta-octyl-glucopyranoside'''<br />
 ==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.
+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==
-G3N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus] with BOG as [http://en.wikipedia.org/wiki/ligand ligand]. 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=2G3N OCA].
+G3N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sulfolobus_solfataricus Sulfolobus solfataricus] with <scene name='pdbligand=BOG:'>BOG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. 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=2G3N OCA].
 ==Reference==
@@ Line 15: / Line 15: @@
 [[Category: Sulfolobus solfataricus]]
 [[Category: Blum, P.]]
-[[Category: Ernst, H.A.]]
+[[Category: Ernst, H A.]]
 [[Category: Larsen, S.]]
-[[Category: Leggio, L.Lo.]]
+[[Category: Leggio, L Lo.]]
 [[Category: Leonard, G.]]
 [[Category: Willemoes, M.]]
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 [[Category: retaining mechanism]]
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