2ojp | pdb_00002ojp

The crystal structure of a dimeric mutant of Dihydrodipicolinate synthase from E.coli- DHDPS-L197Y

spinqualitylabelsall models 2ojp, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ojp is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.7Å Ligands: CSD, GOL, KGC 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). 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 an essential enzyme in (S)-lysine biosynthesis and an important antibiotic target. All X-ray crystal structures solved to date reveal a homotetrameric enzyme. In order to explore the role of this quaternary structure, dimeric variants of Escherichia coli DHDPS were engineered and their properties were compared to those of the wild-type tetrameric form. X-ray crystallography reveals that the active site is not disturbed when the quaternary structure is disrupted. However, the activity of the dimeric enzymes in solution is substantially reduced, and a tetrahedral adduct of a substrate analogue is observed to be trapped at the active site in the crystal form. Remarkably, heating the dimeric enzymes increases activity. We propose that the homotetrameric structure of DHDPS reduces dynamic fluctuations present in the dimeric forms and increases specificity for the first substrate, pyruvate. By restricting motion in a key catalytic motif, a competing, non-productive reaction with a substrate analogue is avoided. Small-angle X-ray scattering and mutagenesis data, together with a B-factor analysis of the crystal structures, support this hypothesis and lead to the suggestion that in at least some cases, the evolution of quaternary enzyme structures might serve to optimise the dynamic properties of the protein subunits. Evolution of quaternary structure in a homotetrameric enzyme.,Griffin MD, Dobson RC, Pearce FG, Antonio L, Whitten AE, Liew CK, Mackay JP, Trewhella J, Jameson GB, Perugini MA, Gerrard JA J Mol Biol. 2008 Jul 18;380(4):691-703. Epub 2008 May 22. PMID:18556019 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Dihydrodipicolinate synthase

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