6r3r: Difference between revisions
No edit summary |
No edit summary |
||
| Line 7: | Line 7: | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6r3r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6r3r OCA], [http://pdbe.org/6r3r PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6r3r RCSB], [http://www.ebi.ac.uk/pdbsum/6r3r PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6r3r ProSAT]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6r3r FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6r3r OCA], [http://pdbe.org/6r3r PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6r3r RCSB], [http://www.ebi.ac.uk/pdbsum/6r3r PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6r3r ProSAT]</span></td></tr> | ||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The endo-levanase BT1760 of a human gut commensal Bacteroides thetaiotaomicron randomly cuts a beta-2,6-linked fructan, levan, into fructo-oligosaccharides providing a prebiotic substrate for gut microbiota. Here we introduce the crystal structure of BT1760 at resolution of 1.65 A. The fold of the enzyme is typical for GH32 family proteins: a catalytic N-terminal five-bladed beta-propeller connected with a C-terminal beta-sandwich domain. The levantetraose-bound structure of catalytically inactive mutant E221A at 1.90-A resolution reveals differences in substrate binding between the endo-acting fructanases. A shallow substrate-binding pocket of the endo-inulinase INU2 of Aspergillus ficuum binds at least three fructose residues at its flat bottom. In the levantetraose-soaked crystal of the endo-levanase E221A mutant the ligand was bent into the pond-like substrate pocket with its fructose residues making contacts at -3, -2, -1 and + 1 subsites residing at several pocket depths. Binding of levantetraose to the beta-sandwich domain was not detected. The N- and C-terminal modules of BT1760 did not bind levan if expressed separately, the catalytic domain lost its activity and both modules tended to precipitate. We gather that endo-levanase BT1760 requires both domains for correct folding, solubility and stability of the protein. | |||
First crystal structure of an endo-levanase - the BT1760 from a human gut commensal Bacteroides thetaiotaomicron.,Ernits K, Eek P, Lukk T, Visnapuu T, Alamae T Sci Rep. 2019 Jun 11;9(1):8443. doi: 10.1038/s41598-019-44785-0. PMID:31186460<ref>PMID:31186460</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 6r3r" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Latest revision as of 10:42, 26 June 2019
First crystal structure of endo-levanase BT1760 from Bacteroides thetaiotaomicronFirst crystal structure of endo-levanase BT1760 from Bacteroides thetaiotaomicron
Structural highlights
Publication Abstract from PubMedThe endo-levanase BT1760 of a human gut commensal Bacteroides thetaiotaomicron randomly cuts a beta-2,6-linked fructan, levan, into fructo-oligosaccharides providing a prebiotic substrate for gut microbiota. Here we introduce the crystal structure of BT1760 at resolution of 1.65 A. The fold of the enzyme is typical for GH32 family proteins: a catalytic N-terminal five-bladed beta-propeller connected with a C-terminal beta-sandwich domain. The levantetraose-bound structure of catalytically inactive mutant E221A at 1.90-A resolution reveals differences in substrate binding between the endo-acting fructanases. A shallow substrate-binding pocket of the endo-inulinase INU2 of Aspergillus ficuum binds at least three fructose residues at its flat bottom. In the levantetraose-soaked crystal of the endo-levanase E221A mutant the ligand was bent into the pond-like substrate pocket with its fructose residues making contacts at -3, -2, -1 and + 1 subsites residing at several pocket depths. Binding of levantetraose to the beta-sandwich domain was not detected. The N- and C-terminal modules of BT1760 did not bind levan if expressed separately, the catalytic domain lost its activity and both modules tended to precipitate. We gather that endo-levanase BT1760 requires both domains for correct folding, solubility and stability of the protein. First crystal structure of an endo-levanase - the BT1760 from a human gut commensal Bacteroides thetaiotaomicron.,Ernits K, Eek P, Lukk T, Visnapuu T, Alamae T Sci Rep. 2019 Jun 11;9(1):8443. doi: 10.1038/s41598-019-44785-0. PMID:31186460[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|
| ||||||||||||||||