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1b9i
From Proteopedia
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| - | [[Image:1b9i.jpg|left|200px]] | ||
| - | + | ==CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE== | |
| - | + | <StructureSection load='1b9i' size='340' side='right'caption='[[1b9i]], [[Resolution|resolution]] 2.00Å' scene=''> | |
| - | + | == Structural highlights == | |
| - | | | + | <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='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='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> | |
| - | + | == Function == | |
| - | + | [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 == | |
| - | + | [[Image:Consurf_key_small.gif|200px|right]] | |
| - | + | Check<jmol> | |
| - | + | <jmolCheckbox> | |
| - | == | + | <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> | ||
| + | <text>to colour the structure by Evolutionary Conservation</text> | ||
| + | </jmolCheckbox> | ||
| + | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1b9i ConSurf]. | ||
| + | <div style="clear:both"></div> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == 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. | 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<ref>PMID:10433690</ref> | |
| - | + | ||
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| + | <div class="pdbe-citations 1b9i" style="background-color:#fffaf0;"></div> | ||
| + | == References == | ||
| + | <references/> | ||
| + | __TOC__ | ||
| + | </StructureSection> | ||
[[Category: Amycolatopsis mediterranei]] | [[Category: Amycolatopsis mediterranei]] | ||
| - | [[Category: | + | [[Category: Large Structures]] |
| - | [[Category: Beeby | + | [[Category: Beeby M]] |
| - | [[Category: Eads | + | [[Category: Eads JC]] |
| - | [[Category: Floss | + | [[Category: Floss HG]] |
| - | [[Category: Scapin | + | [[Category: Scapin G]] |
| - | [[Category: Yu | + | [[Category: Yu T-W]] |
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Current revision
CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE
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