3den

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Structure of E. coli DHDPS mutant Y107WStructure of E. coli DHDPS mutant Y107W

Structural highlights

3den is a 2 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.2Å
Ligands:, , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

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) is a tetrameric enzyme that is the first enzyme unique to the ( S)-lysine biosynthetic pathway in plants and bacteria. Previous studies have looked at the important role of Tyr107, an amino acid residue located at the tight-dimer interface between two monomers, in participating in a catalytic triad of residues during catalysis. In this study, we examine the importance of this residue in determining the quaternary structure of the DHDPS enzyme. The Tyr107 residue was mutated to tryptophan, and structural, biophysical, and kinetic studies were carried out on the mutant enzyme. These revealed that while the solid-state structure of the mutant enzyme was largely unchanged, as judged by X-ray crystallography, it exists as a mixture of primarily monomer and tetramer in solution, as determined by analytical ultracentrifugation, size-exclusion chromatography, and mass spectrometry. The catalytic ability of the DHDPS enzyme was reduced by the mutation, which also allowed the adventitious binding of alpha-ketoglutarate to the active site. A reduction in the apparent melting temperature of the mutant enzyme was observed. Thus, the tetrameric quaternary structure of DHDPS is critical to controlling specificity, heat stability, and intrinsic activity.

Mutating the tight-dimer interface of dihydrodipicolinate synthase disrupts the enzyme quaternary structure: toward a monomeric enzyme.,Pearce FG, Dobson RC, Weber A, Lane LA, McCammon MG, Squire MA, Perugini MA, Jameson GB, Robinson CV, Gerrard JA Biochemistry. 2008 Nov 18;47(46):12108-17. Epub 2008 Oct 21. PMID:18937497[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. 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
  2. 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
  3. Pearce FG, Dobson RC, Weber A, Lane LA, McCammon MG, Squire MA, Perugini MA, Jameson GB, Robinson CV, Gerrard JA. Mutating the tight-dimer interface of dihydrodipicolinate synthase disrupts the enzyme quaternary structure: toward a monomeric enzyme. Biochemistry. 2008 Nov 18;47(46):12108-17. Epub 2008 Oct 21. PMID:18937497 doi:http://dx.doi.org/10.1021/bi801094t

3den, resolution 2.20Å

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