1r8l
From Proteopedia
(New page: 200px<br /><applet load="1r8l" size="450" color="white" frame="true" align="right" spinBox="true" caption="1r8l, resolution 2.6Å" /> '''The structure of endo...) |
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| - | [[Image:1r8l.gif|left|200px]]<br /><applet load="1r8l" size=" | + | [[Image:1r8l.gif|left|200px]]<br /><applet load="1r8l" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1r8l, resolution 2.6Å" /> | caption="1r8l, resolution 2.6Å" /> | ||
'''The structure of endo-beta-1,4-galactanase from Bacillus licheniformis'''<br /> | '''The structure of endo-beta-1,4-galactanase from Bacillus licheniformis'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The beta-1,4-galactanase from Bacillus licheniformis (BLGAL) is a plant | + | The beta-1,4-galactanase from Bacillus licheniformis (BLGAL) is a plant cell-wall-degrading enzyme involved in the hydrolysis of beta-1,4-galactan in the hairy regions of pectin. The crystal structure of BLGAL was determined by molecular replacement both alone and in complex with the products galactobiose and galactotriose, catching a first crystallographic glimpse of fragments of beta-1,4-galactan. As expected for an enzyme belonging to GH-53, the BLGAL structure reveals a (betaalpha)(8)-barrel architecture. However, BLGAL betaalpha-loops 2, 7 and 8 are long in contrast to the corresponding loops in structures of fungal galactanases determined previously. The structure of BLGAL additionally shows a calcium ion linking the long betaalpha-loops 7 and 8, which replaces a disulphide bridge in the fungal galactanases. Compared to the substrate-binding subsites predicted for Aspergillus aculeatus galactanase (AAGAL), two additional subsites for substrate binding are found in BLGAL, -3 and -4. A comparison of the pattern of galactan and galactooligosaccharides degradation by AAGAL and BLGAL shows that, although both are most active on substrates with a high degree of polymerization, AAGAL can degrade galactotriose and galactotetraose efficiently, whereas BLGAL prefers longer oligosaccharides and cannot hydrolyze galactotriose to any appreciable extent. This difference in substrate preference can be explained structurally by the presence of the extra subsites -3 and -4 in BLGAL. |
==About this Structure== | ==About this Structure== | ||
| - | 1R8L is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] with CA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Arabinogalactan_endo-1,4-beta-galactosidase Arabinogalactan endo-1,4-beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.89 3.2.1.89] Full crystallographic information is available from [http:// | + | 1R8L is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis] with <scene name='pdbligand=CA:'>CA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Arabinogalactan_endo-1,4-beta-galactosidase Arabinogalactan endo-1,4-beta-galactosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.89 3.2.1.89] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R8L OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Bjornvad, M.]] | [[Category: Bjornvad, M.]] | ||
| - | [[Category: Christensen, L | + | [[Category: Christensen, L L.]] |
| - | [[Category: Jorgensen, C | + | [[Category: Jorgensen, C T.]] |
[[Category: Larsen, S.]] | [[Category: Larsen, S.]] | ||
| - | [[Category: Leggio, L | + | [[Category: Leggio, L Lo.]] |
| - | [[Category: Nours, J | + | [[Category: Nours, J Le.]] |
[[Category: Ryttersgaard, C.]] | [[Category: Ryttersgaard, C.]] | ||
[[Category: CA]] | [[Category: CA]] | ||
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[[Category: glycosyl hydrolase]] | [[Category: glycosyl hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:48:13 2008'' |
Revision as of 12:48, 21 February 2008
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The structure of endo-beta-1,4-galactanase from Bacillus licheniformis
Overview
The beta-1,4-galactanase from Bacillus licheniformis (BLGAL) is a plant cell-wall-degrading enzyme involved in the hydrolysis of beta-1,4-galactan in the hairy regions of pectin. The crystal structure of BLGAL was determined by molecular replacement both alone and in complex with the products galactobiose and galactotriose, catching a first crystallographic glimpse of fragments of beta-1,4-galactan. As expected for an enzyme belonging to GH-53, the BLGAL structure reveals a (betaalpha)(8)-barrel architecture. However, BLGAL betaalpha-loops 2, 7 and 8 are long in contrast to the corresponding loops in structures of fungal galactanases determined previously. The structure of BLGAL additionally shows a calcium ion linking the long betaalpha-loops 7 and 8, which replaces a disulphide bridge in the fungal galactanases. Compared to the substrate-binding subsites predicted for Aspergillus aculeatus galactanase (AAGAL), two additional subsites for substrate binding are found in BLGAL, -3 and -4. A comparison of the pattern of galactan and galactooligosaccharides degradation by AAGAL and BLGAL shows that, although both are most active on substrates with a high degree of polymerization, AAGAL can degrade galactotriose and galactotetraose efficiently, whereas BLGAL prefers longer oligosaccharides and cannot hydrolyze galactotriose to any appreciable extent. This difference in substrate preference can be explained structurally by the presence of the extra subsites -3 and -4 in BLGAL.
About this Structure
1R8L is a Protein complex structure of sequences from Bacillus licheniformis with as ligand. Active as Arabinogalactan endo-1,4-beta-galactosidase, with EC number 3.2.1.89 Full crystallographic information is available from OCA.
Reference
The structure of endo-beta-1,4-galactanase from Bacillus licheniformis in complex with two oligosaccharide products., Ryttersgaard C, Le Nours J, Lo Leggio L, Jorgensen CT, Christensen LL, Bjornvad M, Larsen S, J Mol Biol. 2004 Jul 30;341(1):107-17. PMID:15312766
Page seeded by OCA on Thu Feb 21 14:48:13 2008
Categories: Arabinogalactan endo-1,4-beta-galactosidase | Bacillus licheniformis | Protein complex | Bjornvad, M. | Christensen, L L. | Jorgensen, C T. | Larsen, S. | Leggio, L Lo. | Nours, J Le. | Ryttersgaard, C. | CA | (beta-alpha)8-barrel | Calcium ion | Clan gh-a | Family 53 | Glycosyl hydrolase
