4ij4

<StructureSection load='4ij4' size='340' side='right' caption='[[4ij4]], [[Resolution|resolution]] 1.58&Aring;' scene=''>

<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='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>

<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>

== References ==

[[Category: Bryum coronatum]]

[[Category: Chitinase]]

[[Category: Fukamizo, T]]

[[Category: Numata, T]]

[[Category: Ohnuma, T]]

[[Category: Umemoto, N]]

[[Category: Hydrolase]]