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| | ==CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE== | | ==CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE== |
| - | <StructureSection load='1b9i' size='340' side='right' caption='[[1b9i]], [[Resolution|resolution]] 2.00Å' scene=''> | + | <StructureSection load='1b9i' size='340' side='right'caption='[[1b9i]], [[Resolution|resolution]] 2.00Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1b9i]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"streptomyces_mediterranei"_margalith_and_beretta_1960 "streptomyces mediterranei" margalith and beretta 1960]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B9I OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1B9I FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1b9i]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Amycolatopsis_mediterranei Amycolatopsis mediterranei]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B9I OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1B9I FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=PXG:3-[O-PHOSPHONOPYRIDOXYL]--AMINO-BENZOIC+ACID'>PXG</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]] 2Å</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=1b9i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b9i OCA], [http://pdbe.org/1b9i PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1b9i RCSB], [http://www.ebi.ac.uk/pdbsum/1b9i PDBsum]</span></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PXG:3-[O-PHOSPHONOPYRIDOXYL]--AMINO-BENZOIC+ACID'>PXG</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=1b9i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1b9i OCA], [https://pdbe.org/1b9i PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1b9i RCSB], [https://www.ebi.ac.uk/pdbsum/1b9i PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1b9i ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/RIFK_AMYMS RIFK_AMYMS]] Catalyzes the dehydration and aromatization of 5-amino-5-deoxy-3-dehydroshikimate (aminoDHS) to 3-amino-5-hydroxybenzoate (AHBA), a compound that then serves as the starter unit for the assembly of a polyketide during the biosynthesis of rifamycin B and other ansamycin antibiotics. Can not utilize 5-deoxy-5-amino-3-dehydroquinate (aminoDHQ), 5-deoxy-5-aminoshikimate (aminoSA), quinate, 3-dehydroquinate, or 3-dehydroshikimate (DHS) as substrate.<ref>PMID:9497318</ref> In a complex with RifL, RifK may have a second function in the AHBA pathway, acting as a transaminase introducing the nitrogen into the first pathway intermediate, UDP-3-keto-D-glucose, to give UDP-kanosamine. Appears to use glutamine as the nitrogen donor; NH(4)+ or asparagine are 30% less effective as nitrogen donors and neither glutamate nor aspartate show activity.<ref>PMID:9497318</ref> | + | [https://www.uniprot.org/uniprot/RIFK_AMYMS RIFK_AMYMS] Catalyzes the dehydration and aromatization of 5-amino-5-deoxy-3-dehydroshikimate (aminoDHS) to 3-amino-5-hydroxybenzoate (AHBA), a compound that then serves as the starter unit for the assembly of a polyketide during the biosynthesis of rifamycin B and other ansamycin antibiotics. Can not utilize 5-deoxy-5-amino-3-dehydroquinate (aminoDHQ), 5-deoxy-5-aminoshikimate (aminoSA), quinate, 3-dehydroquinate, or 3-dehydroshikimate (DHS) as substrate.<ref>PMID:9497318</ref> In a complex with RifL, RifK may have a second function in the AHBA pathway, acting as a transaminase introducing the nitrogen into the first pathway intermediate, UDP-3-keto-D-glucose, to give UDP-kanosamine. Appears to use glutamine as the nitrogen donor; NH(4)+ or asparagine are 30% less effective as nitrogen donors and neither glutamate nor aspartate show activity.<ref>PMID:9497318</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/b9/1b9i_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/b9/1b9i_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Streptomyces mediterranei margalith and beretta 1960]] | + | [[Category: Amycolatopsis mediterranei]] |
| - | [[Category: Beeby, M]] | + | [[Category: Large Structures]] |
| - | [[Category: Eads, J C]] | + | [[Category: Beeby M]] |
| - | [[Category: Floss, H G]] | + | [[Category: Eads JC]] |
| - | [[Category: Scapin, G]] | + | [[Category: Floss HG]] |
| - | [[Category: Yu, T W]] | + | [[Category: Scapin G]] |
| | + | [[Category: Yu T-W]] |
| Structural highlights
Function
RIFK_AMYMS Catalyzes the dehydration and aromatization of 5-amino-5-deoxy-3-dehydroshikimate (aminoDHS) to 3-amino-5-hydroxybenzoate (AHBA), a compound that then serves as the starter unit for the assembly of a polyketide during the biosynthesis of rifamycin B and other ansamycin antibiotics. Can not utilize 5-deoxy-5-amino-3-dehydroquinate (aminoDHQ), 5-deoxy-5-aminoshikimate (aminoSA), quinate, 3-dehydroquinate, or 3-dehydroshikimate (DHS) as substrate.[1] In a complex with RifL, RifK may have a second function in the AHBA pathway, acting as a transaminase introducing the nitrogen into the first pathway intermediate, UDP-3-keto-D-glucose, to give UDP-kanosamine. Appears to use glutamine as the nitrogen donor; NH(4)+ or asparagine are 30% less effective as nitrogen donors and neither glutamate nor aspartate show activity.[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
The biosynthesis of ansamycin antibiotics, including rifamycin B, involves the synthesis of an aromatic precursor, 3-amino-5-hydroxybenzoic acid (AHBA), which serves as starter for the assembly of the antibiotics' polyketide backbone. The terminal enzyme of AHBA formation, AHBA synthase, is a dimeric, pyridoxal 5'-phosphate (PLP) dependent enzyme with pronounced sequence homology to a number of PLP enzymes involved in the biosynthesis of antibiotic sugar moieties. The structure of AHBA synthase from Amycolatopsis mediterranei has been determined to 2.0 A resolution, with bound cofactor, PLP, and in a complex with PLP and an inhibitor (gabaculine). The overall fold of AHBA synthase is similar to that of the aspartate aminotransferase family of PLP-dependent enzymes, with a large domain containing a seven-stranded beta-sheet surrounded by alpha-helices and a smaller domain consisting of a four-stranded antiparallel beta-sheet and four alpha-helices. The uninhibited form of the enzyme shows the cofactor covalently linked to Lys188 in an internal aldimine linkage. On binding the inhibitor, gabaculine, the internal aldimine linkage is broken, and a covalent bond is observed between the cofactor and inhibitor. The active site is composed of residues from two subunits of AHBA synthase, indicating that AHBA synthase is active as a dimer.
Crystal structure of 3-amino-5-hydroxybenzoic acid (AHBA) synthase.,Eads JC, Beeby M, Scapin G, Yu TW, Floss HG Biochemistry. 1999 Aug 3;38(31):9840-9. PMID:10433690[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kim CG, Yu TW, Fryhle CB, Handa S, Floss HG. 3-Amino-5-hydroxybenzoic acid synthase, the terminal enzyme in the formation of the precursor of mC7N units in rifamycin and related antibiotics. J Biol Chem. 1998 Mar 13;273(11):6030-40. PMID:9497318
- ↑ Kim CG, Yu TW, Fryhle CB, Handa S, Floss HG. 3-Amino-5-hydroxybenzoic acid synthase, the terminal enzyme in the formation of the precursor of mC7N units in rifamycin and related antibiotics. J Biol Chem. 1998 Mar 13;273(11):6030-40. PMID:9497318
- ↑ Eads JC, Beeby M, Scapin G, Yu TW, Floss HG. Crystal structure of 3-amino-5-hydroxybenzoic acid (AHBA) synthase. Biochemistry. 1999 Aug 3;38(31):9840-9. PMID:10433690 doi:10.1021/bi990018q
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