3vtr: Difference between revisions
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==Crystal Structure of insect beta-N-acetyl-D-hexosaminidase OfHex1 E328A complexed with TMG-chitotriomycin== | |||
<StructureSection load='3vtr' size='340' side='right'caption='[[3vtr]], [[Resolution|resolution]] 2.50Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3vtr]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ostrinia_furnacalis Ostrinia furnacalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3VTR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3VTR FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PRD_900080:TMG-chitotriomycin'>PRD_900080</scene>, <scene name='pdbligand=TMX:2-DEOXY-2-(TRIMETHYLAMMONIO)-BETA-D-GLUCOPYRANOSE'>TMX</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3vtr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3vtr OCA], [https://pdbe.org/3vtr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3vtr RCSB], [https://www.ebi.ac.uk/pdbsum/3vtr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3vtr ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/HEXC_OSTFU HEXC_OSTFU] Hydrolyzes one beta-GlcNAc unit at a time from the non-reducing ends of substrates, with a preference for shorter substrates. The 2-acetamido group and the beta-glycoside bond linkage in the substrate are required for its activity. Active with p-nitrophenyl (pNP)-beta-GlcNAc, pNP-beta-GalNAc and chitooligosaccharides (degree of polymerization from 2 to 6), but not with the complex N-glycan substrate (GlcNAcbeta-1,2Manalpha-1,6)(GlcNAcbeta-1,2Manalpha-1,3)Manbeta-1,4GlcNAcbeta-1,4GlcNAc-PA (GnGn-PA), pNP-alpha-GlcNAc or with the long polymer colloidal chitin. Involved in chitin catabolism (PubMed:18959754). Involved in the degradation of old cuticle during the pupation stage (PubMed:21106526).<ref>PMID:18959754</ref> <ref>PMID:21106526</ref> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The chemical similarity of cellulose and chitin supports the idea that their corresponding hydrolytic enzymes would bind beta-1,4-linked glucose residues in a similar manner. A structural and mutational analysis was performed for the plant cellulolytic enzyme BGlu1 from Oryza sativa and the insect chitinolytic enzyme OfHex1 from Ostrinia furnacalis. Although BGlu1 shows little amino-acid sequence or topological similarity with OfHex1, three residues (Trp(490), Glu(328), Val(327) in OfHex1, and Trp(358), Tyr(131) and Ile(179) in BGlu1) were identified as being conserved in the +1 sugar binding site. OfHex1 Glu(328) together with Trp(490) was confirmed to be necessary for substrate binding. The mutant E328A exhibited a 8-fold increment in K(m) for (GlcNAc)(2) and a 42-fold increment in K(i) for TMG-chitotriomycin. A crystal structure of E328A in complex with TMG-chitotriomycin was resolved at 2.5 A, revealing the obvious conformational changes of the catalytic residues (Glu(368) and Asp(367)) and the absence of the hydrogen bond between E328A and the C3-OH of the +1 sugar. V327G exhibited the same activity as the wild-type, but acquired the ability to efficiently hydrolyse beta-1,2-linked GlcNAc in contrast to the wild-type. Thus, Glu(328) and Val(327) were identified as important for substrate-binding and as glycosidic-bond determinants. A structure-based sequence alignment confirmed the spatial conservation of these three residues in most plant cellulolytic, insect and bacterial chitinolytic enzymes. | |||
Structural insights into cellulolytic and chitinolytic enzymes revealing crucial residues of insect beta-N-acetyl-D-hexosaminidase.,Liu T, Zhou Y, Chen L, Chen W, Liu L, Shen X, Zhang W, Zhang J, Yang Q PLoS One. 2012;7(12):e52225. doi: 10.1371/journal.pone.0052225. Epub 2012 Dec 27. PMID:23300622<ref>PMID:23300622</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3vtr" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
[[ | *[[Beta-N-acetylhexosaminidase 3D structures|Beta-N-acetylhexosaminidase 3D structures]] | ||
[[Category: | == References == | ||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Ostrinia furnacalis]] | [[Category: Ostrinia furnacalis]] | ||
[[Category: Chen | [[Category: Chen L]] | ||
[[Category: Chen | [[Category: Chen W]] | ||
[[Category: Liu | [[Category: Liu L]] | ||
[[Category: Liu | [[Category: Liu T]] | ||
[[Category: Shen | [[Category: Shen X]] | ||
[[Category: Yang | [[Category: Yang Q]] | ||
[[Category: Zhou | [[Category: Zhou Y]] | ||
