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==Crystal Structure of a Family GH19 chitinase from Bryum coronatum in complex with (GlcNAc)4== | |||
=== | <StructureSection load='4ij4' size='340' side='right' caption='[[4ij4]], [[Resolution|resolution]] 1.58Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4ij4]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bryum_coronatum Bryum coronatum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IJ4 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4IJ4 FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | |||
<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene></td></tr> | |||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3wh1|3wh1]]</td></tr> | |||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bcchiA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=216087 Bryum coronatum])</td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Chitinase Chitinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.14 3.2.1.14] </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=4ij4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ij4 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4ij4 RCSB], [http://www.ebi.ac.uk/pdbsum/4ij4 PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
DESCRIPTIONS: The structure of a GH19 chitinase from the moss Bryum coronatum (BcChi-A) in complex with the substrate was examined by X-ray crystallography and NMR spectroscopy in solution. The X-ray crystal structure of the inactive mutant of BcChi-A (BcChi-A-E61A) liganded with chitin tetramer (GlcNAc)4 revealed a clear electron density of the tetramer bound to subsites -2, -1, +1, and +2. Individual sugar residues were recognized by several amino acids at these subsites through a number of hydrogen bonds. This is the first crystal structure of GH19 chitinase liganded with oligosaccharide spanning the catalytic center. NMR titration experiments of chitin oligosaccharides into the BcChi-A-E61A solution showed that the binding mode observed in the crystal structure is similar to that in solution. The C-1 carbon of -1 GlcNAc, the Oepsilon1 atom of the catalytic base (Glu70), and the Ogamma atom of Ser102 form a "triangle" surrounding the catalytic water, and the arrangement structurally validated the proposed catalytic mechanism of GH19 chitinases. The glycosidic linkage between -1 and +1 sugars was found to be twisted and under strain. This situation may contribute to the reduction of activation energy for hydrolysis. The complex structure revealed a more refined mechanism of the chitinase catalysis. | |||
Crystal structure of a "loopless" GH19 chitinase in complex with chitin tetrasaccharide spanning the catalytic center.,Ohnuma T, Umemoto N, Nagata T, Shinya S, Numata T, Taira T, Fukamizo T Biochim Biophys Acta. 2014 Feb 25;1844(4):793-802. doi:, 10.1016/j.bbapap.2014.02.013. PMID:24582745<ref>PMID:24582745</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Bryum coronatum]] | |||
[[Category: Chitinase]] | [[Category: Chitinase]] | ||
[[Category: Fukamizo, T | [[Category: Fukamizo, T]] | ||
[[Category: Numata, T | [[Category: Numata, T]] | ||
[[Category: Ohnuma, T | [[Category: Ohnuma, T]] | ||
[[Category: Umemoto, N | [[Category: Umemoto, N]] | ||
[[Category: Carbohydrate]] | [[Category: Carbohydrate]] | ||
[[Category: Hydrolase]] | [[Category: Hydrolase]] | ||
Revision as of 11:05, 25 January 2015
Crystal Structure of a Family GH19 chitinase from Bryum coronatum in complex with (GlcNAc)4Crystal Structure of a Family GH19 chitinase from Bryum coronatum in complex with (GlcNAc)4
Structural highlights
Publication Abstract from PubMedDESCRIPTIONS: The structure of a GH19 chitinase from the moss Bryum coronatum (BcChi-A) in complex with the substrate was examined by X-ray crystallography and NMR spectroscopy in solution. The X-ray crystal structure of the inactive mutant of BcChi-A (BcChi-A-E61A) liganded with chitin tetramer (GlcNAc)4 revealed a clear electron density of the tetramer bound to subsites -2, -1, +1, and +2. Individual sugar residues were recognized by several amino acids at these subsites through a number of hydrogen bonds. This is the first crystal structure of GH19 chitinase liganded with oligosaccharide spanning the catalytic center. NMR titration experiments of chitin oligosaccharides into the BcChi-A-E61A solution showed that the binding mode observed in the crystal structure is similar to that in solution. The C-1 carbon of -1 GlcNAc, the Oepsilon1 atom of the catalytic base (Glu70), and the Ogamma atom of Ser102 form a "triangle" surrounding the catalytic water, and the arrangement structurally validated the proposed catalytic mechanism of GH19 chitinases. The glycosidic linkage between -1 and +1 sugars was found to be twisted and under strain. This situation may contribute to the reduction of activation energy for hydrolysis. The complex structure revealed a more refined mechanism of the chitinase catalysis. Crystal structure of a "loopless" GH19 chitinase in complex with chitin tetrasaccharide spanning the catalytic center.,Ohnuma T, Umemoto N, Nagata T, Shinya S, Numata T, Taira T, Fukamizo T Biochim Biophys Acta. 2014 Feb 25;1844(4):793-802. doi:, 10.1016/j.bbapap.2014.02.013. PMID:24582745[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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