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| | ==Benzalacetone synthase from Rheum palmatum== | | ==Benzalacetone synthase from Rheum palmatum== |
| - | <StructureSection load='3a5q' size='340' side='right' caption='[[3a5q]], [[Resolution|resolution]] 1.80Å' scene=''> | + | <StructureSection load='3a5q' size='340' side='right'caption='[[3a5q]], [[Resolution|resolution]] 1.80Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3a5q]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Chinese_rhubarb Chinese rhubarb]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3A5Q OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3A5Q FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3a5q]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Chinese_rhubarb Chinese rhubarb]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3A5Q OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3A5Q FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1cgk|1cgk]], [[1u0u|1u0u]], [[2d3m|2d3m]], [[3a5r|3a5r]], [[3a5s|3a5s]]</td></tr> | + | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1cgk|1cgk]], [[1u0u|1u0u]], [[2d3m|2d3m]], [[3a5r|3a5r]], [[3a5s|3a5s]]</div></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bas ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=137221 Chinese rhubarb])</td></tr> | + | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bas ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=137221 Chinese rhubarb])</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=3a5q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3a5q OCA], [http://pdbe.org/3a5q PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3a5q RCSB], [http://www.ebi.ac.uk/pdbsum/3a5q PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3a5q 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=3a5q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3a5q OCA], [https://pdbe.org/3a5q PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3a5q RCSB], [https://www.ebi.ac.uk/pdbsum/3a5q PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3a5q ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/BAS_RHEPA BAS_RHEPA]] Polyketide synthase producing 4-hydroxybenzalacetone. Can use p-coumaryl-CoA as substrate but does not accept hexanoyl-CoA, isobutyryl-CoA, isovaleryl-CoA, and acetyl-CoA as a substrates. Catalyzes the initial key reaction step in the biosynthesis of phenylbutanoids.<ref>PMID:11389739</ref> <ref>PMID:17383877</ref> | + | [[https://www.uniprot.org/uniprot/BAS_RHEPA BAS_RHEPA]] Polyketide synthase producing 4-hydroxybenzalacetone. Can use p-coumaryl-CoA as substrate but does not accept hexanoyl-CoA, isobutyryl-CoA, isovaleryl-CoA, and acetyl-CoA as a substrates. Catalyzes the initial key reaction step in the biosynthesis of phenylbutanoids.<ref>PMID:11389739</ref> <ref>PMID:17383877</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Chinese rhubarb]] | | [[Category: Chinese rhubarb]] |
| | + | [[Category: Large Structures]] |
| | [[Category: Abe, I]] | | [[Category: Abe, I]] |
| | [[Category: Kato, R]] | | [[Category: Kato, R]] |
| Structural highlights
Function
[BAS_RHEPA] Polyketide synthase producing 4-hydroxybenzalacetone. Can use p-coumaryl-CoA as substrate but does not accept hexanoyl-CoA, isobutyryl-CoA, isovaleryl-CoA, and acetyl-CoA as a substrates. Catalyzes the initial key reaction step in the biosynthesis of phenylbutanoids.[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
Benzalacetone synthase (BAS), a plant-specific type III polyketide synthase (PKS), catalyzes a one-step decarboxylative condensation of malonyl-CoA and 4-coumaroyl-CoA to produce the diketide benzalacetone. We solved the crystal structures of both the wild-type and chalcone-producing I207L/L208F mutant of Rheum palmatum BAS at 1.8 A resolution. In addition, we solved the crystal structure of the wild-type enzyme, in which a monoketide coumarate intermediate is covalently bound to the catalytic cysteine residue, at 1.6 A resolution. This is the first direct evidence that type III PKS utilizes the cysteine as the nucleophile and as the attachment site for the polyketide intermediate. The crystal structures revealed that BAS utilizes an alternative, novel active-site pocket for locking the aromatic moiety of the coumarate, instead of the chalcone synthase's coumaroyl-binding pocket, which is lost in the active-site of the wild-type enzyme and restored in the I207L/L208F mutant. Furthermore, the crystal structures indicated the presence of a putative nucleophilic water molecule which forms hydrogen bond networks with the Cys-His-Asn catalytic triad. This suggested that BAS employs novel catalytic machinery for the thioester bond cleavage of the enzyme-bound diketide intermediate and the final decarboxylation reaction to produce benzalacetone. These findings provided a structural basis for the functional diversity of the type III PKS enzymes.
A structure-based mechanism for benzalacetone synthase from Rheum palmatum.,Morita H, Shimokawa Y, Tanio M, Kato R, Noguchi H, Sugio S, Kohno T, Abe I Proc Natl Acad Sci U S A. 2010 Jan 12;107(2):669-73. Epub 2009 Dec 18. PMID:20080733[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Abe I, Takahashi Y, Morita H, Noguchi H. Benzalacetone synthase. A novel polyketide synthase that plays a crucial role in the biosynthesis of phenylbutanones in Rheum palmatum. Eur J Biochem. 2001 Jun;268(11):3354-9. PMID:11389739
- ↑ Abe T, Morita H, Noma H, Kohno T, Noguchi H, Abe I. Structure function analysis of benzalacetone synthase from Rheum palmatum. Bioorg Med Chem Lett. 2007 Jun 1;17(11):3161-6. Epub 2007 Mar 15. PMID:17383877 doi:http://dx.doi.org/10.1016/j.bmcl.2007.03.029
- ↑ Morita H, Shimokawa Y, Tanio M, Kato R, Noguchi H, Sugio S, Kohno T, Abe I. A structure-based mechanism for benzalacetone synthase from Rheum palmatum. Proc Natl Acad Sci U S A. 2010 Jan 12;107(2):669-73. Epub 2009 Dec 18. PMID:20080733 doi:10.1073/pnas.0909982107
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