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| | ==2.4 A Crystal structure of E. coli MltE-E64Q with bound chitopentaose== | | ==2.4 A Crystal structure of E. coli MltE-E64Q with bound chitopentaose== |
| - | <StructureSection load='4hjy' size='340' side='right' caption='[[4hjy]], [[Resolution|resolution]] 2.40Å' scene=''> | + | <StructureSection load='4hjy' size='340' side='right'caption='[[4hjy]], [[Resolution|resolution]] 2.40Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4hjy]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Ecoli Ecoli]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=3t1z 3t1z]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HJY OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4HJY FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4hjy]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=3t1z 3t1z]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HJY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HJY FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | + | </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_900017:triacetyl-beta-chitotriose'>PRD_900017</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3t36|3t36]], [[4hjv|4hjv]], [[4hjz|4hjz]]</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=4hjy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hjy OCA], [https://pdbe.org/4hjy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hjy RCSB], [https://www.ebi.ac.uk/pdbsum/4hjy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hjy ProSAT]</span></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">emtA, mltE, sltZ, ycgP, b1193, JW5821 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 ECOLI])</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=4hjy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hjy OCA], [http://pdbe.org/4hjy PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4hjy RCSB], [http://www.ebi.ac.uk/pdbsum/4hjy PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4hjy ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/EMTA_ECOLI EMTA_ECOLI]] Murein-degrading enzyme. May play a role in recycling of muropeptides during cell elongation and/or cell division. Preferentially cleaves at a distance of more than two disaccharide units from the ends of the glycan chain. Prefers cross-linked murein in vivo. | + | [https://www.uniprot.org/uniprot/EMTA_ECOLI EMTA_ECOLI] Murein-degrading enzyme. May play a role in recycling of muropeptides during cell elongation and/or cell division. Preferentially cleaves at a distance of more than two disaccharide units from the ends of the glycan chain. Prefers cross-linked murein in vivo. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Ecoli]] | + | [[Category: Escherichia coli K-12]] |
| - | [[Category: Fibriansah, G]] | + | [[Category: Large Structures]] |
| - | [[Category: Gliubich, F I]] | + | [[Category: Fibriansah G]] |
| - | [[Category: Thunnissen, A M.W H]] | + | [[Category: Gliubich FI]] |
| - | [[Category: Goose lysozyme-like structure]] | + | [[Category: Thunnissen A-MWH]] |
| - | [[Category: Lyase]]
| + | |
| - | [[Category: Lytic transglycosylase]]
| + | |
| Structural highlights
Function
EMTA_ECOLI Murein-degrading enzyme. May play a role in recycling of muropeptides during cell elongation and/or cell division. Preferentially cleaves at a distance of more than two disaccharide units from the ends of the glycan chain. Prefers cross-linked murein in vivo.
Publication Abstract from PubMed
The lytic transglycosylase MltE from Escherichia coli is a periplasmic, outer membrane-attached enzyme that cleaves the beta-1,4-glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine residues in the cell wall peptidoglycan, producing 1,6-anhydromuropeptides. Here we report three crystal structures of MltE: in a substrate-free state, in a binary complex with chitopentaose, and in a ternary complex with the glycopeptide inhibitor bulgecin A and the murodipeptide N-acetylglucosaminyl-N-acetylmuramyl-l-Ala-d-Glu. The substrate-bound structures allowed a detailed analysis of the saccharide-binding interactions in six subsites of the peptidoglycan-binding groove (subsites -4 to +2) and, combined with site-directed mutagenesis analysis, confirmed the role of Glu64 as catalytic acid/base. The structures permitted the precise modeling of a short glycan strand of eight saccharide residues, providing evidence for two additional subsites (+3 and +4) and revealing the productive conformational state of the substrate at subsites -1 and +1, where the glycosidic bond is cleaved. Full accessibility of the peptidoglycan-binding groove and preferential binding of an N-acetylmuramic acid residue in a (4)C(1) chair conformation at subsite +2 explain why MltE shows only endo- and no exo-specific activity toward glycan strands. The results further indicate that catalysis of glycosidic bond cleavage by MltE proceeds via distortion toward a sofa-like conformation of the N-acetylmuramic acid sugar ring at subsite -1 and by anchimeric assistance of the sugar's N-acetyl group, as shown previously for the lytic transglycosylases Slt70 and MltB.
On the Mechanism of Peptidoglycan Binding and Cleavage by the endo-Specific Lytic Transglycosylase MltE from Escherichia coli.,Fibriansah G, Gliubich FI, Thunnissen AM Biochemistry. 2012 Oct 30. PMID:23075328[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Fibriansah G, Gliubich FI, Thunnissen AM. On the Mechanism of Peptidoglycan Binding and Cleavage by the endo-Specific Lytic Transglycosylase MltE from Escherichia coli. Biochemistry. 2012 Oct 30. PMID:23075328 doi:http://dx.doi.org/10.1021/bi300900t
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