This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1b9i
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1b9i.jpg|left|200px]] | [[Image:1b9i.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1b9i", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | | | + | --> |
| - | + | {{STRUCTURE_1b9i| PDB=1b9i | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE''' | '''CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE''' | ||
| Line 30: | Line 27: | ||
[[Category: Scapin, G.]] | [[Category: Scapin, G.]] | ||
[[Category: Yu, T W.]] | [[Category: Yu, T W.]] | ||
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 11:14:37 2008'' | |
| - | + | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 08:14, 2 May 2008
CRYSTAL STRUCTURE OF 3-AMINO-5-HYDROXYBENZOIC ACID (AHBA) SYNTHASE
Overview
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.
About this Structure
1B9I is a Single protein structure of sequence from Amycolatopsis mediterranei. Full crystallographic information is available from OCA.
Reference
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 Page seeded by OCA on Fri May 2 11:14:37 2008
