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| | ==Crystal structure of the P228A variant of Thermotoga maritima acetyl esterase== | | ==Crystal structure of the P228A variant of Thermotoga maritima acetyl esterase== |
| - | <StructureSection load='5gma' size='340' side='right' caption='[[5gma]], [[Resolution|resolution]] 2.10Å' scene=''> | + | <StructureSection load='5gma' size='340' side='right'caption='[[5gma]], [[Resolution|resolution]] 2.10Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5gma]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Thema Thema]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GMA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5GMA FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5gma]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermotoga_maritima_MSB8 Thermotoga maritima MSB8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GMA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5GMA FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.1Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[5fdf|5fdf]], [[5jib|5jib]], [[5hfn|5hfn]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">axeA, TM_0077 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=243274 THEMA])</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=5gma FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5gma OCA], [https://pdbe.org/5gma PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5gma RCSB], [https://www.ebi.ac.uk/pdbsum/5gma PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5gma ProSAT]</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=5gma FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5gma OCA], [http://pdbe.org/5gma PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5gma RCSB], [http://www.ebi.ac.uk/pdbsum/5gma PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5gma ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/CAH_THEMA CAH_THEMA]] Esterase that removes acetyl groups from a number of O-acetylated small substrates, such as acetylated xylose, short xylo-oligosaccharides and cephalosporin C. Has no activity towards polymeric acetylated xylan, 4-methylumbelliferyl acetate or alpha-naphthyl acetate. Able to catalyze rapid hydrolysis of a range of substrates preferably with acetate groups, independent of the alcohol moiety. Exhibits a narrow selectivity for short chain acyl esters (C2-C3). Displays broad substrate specificity by hydrolyzing acetate at 2, 3, and 4 positions of 4-nitrophenyl-beta-D-xylopyranoside (pNP-Xyl) with similar efficiency. Cannot cleave amide linkages.<ref>PMID:21255309</ref> <ref>PMID:22411095</ref> <ref>PMID:22659119</ref> | + | [https://www.uniprot.org/uniprot/CAH_THEMA CAH_THEMA] Esterase that removes acetyl groups from a number of O-acetylated small substrates, such as acetylated xylose, short xylo-oligosaccharides and cephalosporin C. Has no activity towards polymeric acetylated xylan, 4-methylumbelliferyl acetate or alpha-naphthyl acetate. Able to catalyze rapid hydrolysis of a range of substrates preferably with acetate groups, independent of the alcohol moiety. Exhibits a narrow selectivity for short chain acyl esters (C2-C3). Displays broad substrate specificity by hydrolyzing acetate at 2, 3, and 4 positions of 4-nitrophenyl-beta-D-xylopyranoside (pNP-Xyl) with similar efficiency. Cannot cleave amide linkages.<ref>PMID:21255309</ref> <ref>PMID:22411095</ref> <ref>PMID:22659119</ref> |
| | <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: Thema]] | + | [[Category: Large Structures]] |
| - | [[Category: Manoj, N]] | + | [[Category: Thermotoga maritima MSB8]] |
| - | [[Category: Carbohydrate metabolism]] | + | [[Category: Manoj N]] |
| - | [[Category: Cephalosporin deacetylase]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Rossmann fold]]
| + | |
| Structural highlights
Function
CAH_THEMA Esterase that removes acetyl groups from a number of O-acetylated small substrates, such as acetylated xylose, short xylo-oligosaccharides and cephalosporin C. Has no activity towards polymeric acetylated xylan, 4-methylumbelliferyl acetate or alpha-naphthyl acetate. Able to catalyze rapid hydrolysis of a range of substrates preferably with acetate groups, independent of the alcohol moiety. Exhibits a narrow selectivity for short chain acyl esters (C2-C3). Displays broad substrate specificity by hydrolyzing acetate at 2, 3, and 4 positions of 4-nitrophenyl-beta-D-xylopyranoside (pNP-Xyl) with similar efficiency. Cannot cleave amide linkages.[1] [2] [3]
Publication Abstract from PubMed
A conserved cis proline residue located in the active site of Thermotoga maritima acetyl esterase (TmAcE) from the carbohydrate esterase family 7 (CE7) has been substituted by alanine. The residue was known to play a crucial role in determining the catalytic properties of the enzyme. To elucidate the structural role of the residue, the crystal structure of the Pro228Ala variant (TmAcEP228A ) was determined at 2.1 A resolution. The replacement does not affect the overall secondary, tertiary, and quaternary structures and moderately decreases the thermal stability. However, the wild type cis conformation of the 227-228 peptide bond adopts a trans conformation in the variant. Other conformational changes in the tertiary structure are restricted to residues 222-226, preceding this peptide bond and are located away from the active site. Overall, the results suggest that the conserved proline residue is responsible for the cis conformation of the peptide and shapes the geometry of the active site. Elimination of the pyrrolidine ring results in the loss of van der Waals and hydrophobic interactions with both the alcohol and acyl moeities of the ester substrate, leading to significant impairment of the activity and perturbation of substrate specificity. Furthermore, a cis-to-trans conformational change arising out of residue changes at this position may be associated with the evolution of divergent activity, specificity, and stability properties of members constituting the CE7 family. Proteins 2017; 85:694-708. (c) 2016 Wiley Periodicals, Inc.
Structural role of a conserved active site cis proline in the Thermotoga maritima acetyl esterase from the carbohydrate esterase family 7.,Singh MK, Manoj N Proteins. 2017 Apr;85(4):694-708. doi: 10.1002/prot.25249. Epub 2017 Feb 6. PMID:28097692[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Drzewiecki K, Angelov A, Ballschmiter M, Tiefenbach KJ, Sterner R, Liebl W. Hyperthermostable acetyl xylan esterase. Microb Biotechnol. 2010 Jan;3(1):84-92. doi: 10.1111/j.1751-7915.2009.00150.x., Epub 2009 Sep 18. PMID:21255309 doi:http://dx.doi.org/10.1111/j.1751-7915.2009.00150.x
- ↑ Levisson M, Han GW, Deller MC, Xu Q, Biely P, Hendriks S, Ten Eyck LF, Flensburg C, Roversi P, Miller MD, McMullan D, von Delft F, Kreusch A, Deacon AM, van der Oost J, Lesley SA, Elsliger MA, Kengen SW, Wilson IA. Functional and structural characterization of a thermostable acetyl esterase from Thermotoga maritima. Proteins. 2012 Jan 27. doi: 10.1002/prot.24041. PMID:22411095 doi:10.1002/prot.24041
- ↑ Hedge MK, Gehring AM, Adkins CT, Weston LA, Lavis LD, Johnson RJ. The structural basis for the narrow substrate specificity of an acetyl esterase from Thermotoga maritima. Biochim Biophys Acta. 2012 Sep;1824(9):1024-30. doi:, 10.1016/j.bbapap.2012.05.009. Epub 2012 Jun 1. PMID:22659119 doi:http://dx.doi.org/10.1016/j.bbapap.2012.05.009
- ↑ Singh MK, Manoj N. Structural role of a conserved active site cis proline in the Thermotoga maritima acetyl esterase from the carbohydrate esterase family 7. Proteins. 2017 Apr;85(4):694-708. doi: 10.1002/prot.25249. Epub 2017 Feb 6. PMID:28097692 doi:http://dx.doi.org/10.1002/prot.25249
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