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| | <StructureSection load='1f6d' size='340' side='right'caption='[[1f6d]], [[Resolution|resolution]] 2.50Å' scene=''> | | <StructureSection load='1f6d' size='340' side='right'caption='[[1f6d]], [[Resolution|resolution]] 2.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1f6d]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F6D OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1F6D FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1f6d]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F6D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1F6D FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=UDP:URIDINE-5-DIPHOSPHATE'>UDP</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='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='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/UDP-N-acetylglucosamine_2-epimerase_(non-hydrolyzing) UDP-N-acetylglucosamine 2-epimerase (non-hydrolyzing)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.14 5.1.3.14] </span></td></tr> | + | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/UDP-N-acetylglucosamine_2-epimerase_(non-hydrolyzing) UDP-N-acetylglucosamine 2-epimerase (non-hydrolyzing)], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.1.3.14 5.1.3.14] </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=1f6d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1f6d OCA], [http://pdbe.org/1f6d PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1f6d RCSB], [http://www.ebi.ac.uk/pdbsum/1f6d PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1f6d ProSAT]</span></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=1f6d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1f6d OCA], [https://pdbe.org/1f6d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1f6d RCSB], [https://www.ebi.ac.uk/pdbsum/1f6d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1f6d ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/WECB_ECOLI WECB_ECOLI]] Catalyzes the reversible epimerization at C-2 of UDP-N-acetylglucosamine (UDP-GlcNAc) and thereby provides bacteria with UDP-N-acetylmannosamine (UDP-ManNAc), the activated donor of ManNAc residues. Also involved in bacteriophage N4 adsorption.<ref>PMID:7559340</ref> <ref>PMID:8170390</ref> | + | [[https://www.uniprot.org/uniprot/WECB_ECOLI WECB_ECOLI]] Catalyzes the reversible epimerization at C-2 of UDP-N-acetylglucosamine (UDP-GlcNAc) and thereby provides bacteria with UDP-N-acetylmannosamine (UDP-ManNAc), the activated donor of ManNAc residues. Also involved in bacteriophage N4 adsorption.<ref>PMID:7559340</ref> <ref>PMID:8170390</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| Structural highlights
Function
[WECB_ECOLI] Catalyzes the reversible epimerization at C-2 of UDP-N-acetylglucosamine (UDP-GlcNAc) and thereby provides bacteria with UDP-N-acetylmannosamine (UDP-ManNAc), the activated donor of ManNAc residues. Also involved in bacteriophage N4 adsorption.[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Bacterial UDP-N-acetylglucosamine 2-epimerase catalyzes the reversible epimerization at C-2 of UDP-N-acetylglucosamine (UDP-GlcNAc) and thereby provides bacteria with UDP-N-acetylmannosamine (UDP-ManNAc), the activated donor of ManNAc residues. ManNAc is critical for several processes in bacteria, including formation of the antiphagocytic capsular polysaccharide of pathogens such as Streptococcus pneumoniae types 19F and 19A. We have determined the X-ray structure (2.5 A) of UDP-GlcNAc 2-epimerase with bound UDP and identified a previously unsuspected structural homology with the enzymes glycogen phosphorylase and T4 phage beta-glucosyltransferase. The relationship to these phosphoglycosyl transferases is very intriguing in terms of possible similarities in the catalytic mechanisms. Specifically, this observation is consistent with the proposal that the UDP-GlcNAc 2-epimerase-catalyzed elimination and re-addition of UDP to the glycal intermediate may proceed through a transition state with significant oxocarbenium ion-like character. The homodimeric epimerase is composed of two similar alpha/beta/alpha sandwich domains with the active site located in the deep cleft at the domain interface. Comparison of the multiple copies in the asymmetric unit has revealed that the epimerase can undergo a 10 degrees interdomain rotation that is implicated in the regulatory mechanism. A structure-based sequence alignment has identified several basic residues in the active site that may be involved in the proton transfer at C-2 or stabilization of the proposed oxocarbenium ion-like transition state. This insight into the structure of the bacterial epimerase is applicable to the homologous N-terminal domain of the bifunctional mammalian UDP-GlcNAc "hydrolyzing" 2-epimerase/ManNAc kinase that catalyzes the rate-determining step in the sialic acid biosynthetic pathway.
The structure of UDP-N-acetylglucosamine 2-epimerase reveals homology to phosphoglycosyl transferases.,Campbell RE, Mosimann SC, Tanner ME, Strynadka NC Biochemistry. 2000 Dec 12;39(49):14993-5001. PMID:11106477[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Marolda CL, Valvano MA. Genetic analysis of the dTDP-rhamnose biosynthesis region of the Escherichia coli VW187 (O7:K1) rfb gene cluster: identification of functional homologs of rfbB and rfbA in the rff cluster and correct location of the rffE gene. J Bacteriol. 1995 Oct;177(19):5539-46. PMID:7559340
- ↑ Macpherson DF, Manning PA, Morona R. Characterization of the dTDP-rhamnose biosynthetic genes encoded in the rfb locus of Shigella flexneri. Mol Microbiol. 1994 Jan;11(2):281-92. PMID:8170390
- ↑ Campbell RE, Mosimann SC, Tanner ME, Strynadka NC. The structure of UDP-N-acetylglucosamine 2-epimerase reveals homology to phosphoglycosyl transferases. Biochemistry. 2000 Dec 12;39(49):14993-5001. PMID:11106477
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