<text>to colour the structure by Evolutionary Conservation</text>
<text>to colour the structure by Evolutionary Conservation</text>
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</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/chain_selection.php?pdb_ID=2ata ConSurf].
</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=1s5v ConSurf].
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Revision as of 02:19, 9 February 2016
Crystal Structure Analysis of a mutant of DIHYDRODIPICOLINATE SYNTHASE--residue Tyr107 to Phe107
[DAPA_ECOLI] Catalyzes the condensation of (S)-aspartate-beta-semialdehyde [(S)-ASA] and pyruvate to 4-hydroxy-tetrahydrodipicolinate (HTPA).[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
Dihydrodipicolinate synthase (DHDPS, EC 4.2.1.52) catalyses the branchpoint reaction of lysine biosynthesis in plants and microbes: the condensation of (S)-aspartate-beta-semialdehyde and pyruvate. The crystal structure of wild-type DHDPS has been published to 2.5A, revealing a tetrameric molecule comprised of four identical (beta/alpha)(8)-barrels, each containing one active site. Previous workers have hypothesised that the catalytic mechanism of the enzyme involves a catalytic triad of amino acid residues, Tyr133, Thr44 and Tyr107, which provide a proton shuttle to transport protons from the active site to solvent. We have tested this hypothesis using site-directed mutagenesis to produce three mutant enzymes: DHDPS-Y133F, DHDPS-T44V and DHDPS-Y107F. Each of these mutants has substantially reduced activity, consistent with the catalytic triad hypothesis. We have determined each mutant crystal structure to at least 2.35A resolution and compared the structures to the wild-type enzyme. All mutant enzymes crystallised in the same space group as the wild-type form and only minor differences in structure are observed. These results suggest that the catalytic triad is indeed in operation in wild-type DHDPS.
The crystal structure of three site-directed mutants of Escherichia coli dihydrodipicolinate synthase: further evidence for a catalytic triad.,Dobson RC, Valegard K, Gerrard JA J Mol Biol. 2004 Apr 23;338(2):329-39. PMID:15066435[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Devenish SR, Blunt JW, Gerrard JA. NMR studies uncover alternate substrates for dihydrodipicolinate synthase and suggest that dihydrodipicolinate reductase is also a dehydratase. J Med Chem. 2010 Jun 24;53(12):4808-12. doi: 10.1021/jm100349s. PMID:20503968 doi:10.1021/jm100349s
↑Blickling S, Renner C, Laber B, Pohlenz HD, Holak TA, Huber R. Reaction mechanism of Escherichia coli dihydrodipicolinate synthase investigated by X-ray crystallography and NMR spectroscopy. Biochemistry. 1997 Jan 7;36(1):24-33. PMID:8993314 doi:10.1021/bi962272d
↑Dobson RC, Valegard K, Gerrard JA. The crystal structure of three site-directed mutants of Escherichia coli dihydrodipicolinate synthase: further evidence for a catalytic triad. J Mol Biol. 2004 Apr 23;338(2):329-39. PMID:15066435 doi:https://dx.doi.org/10.1016/j.jmb.2004.02.060