2q9h

Crystal structure of the C73S mutant of diaminopimelate epimerase

spinqualitylabelsall models 2q9h, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2q9h is a 1 chain structure with sequence from Haemophilus influenzae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ACY, TLA Related: 2gke, 2gkj, 1gqz, 1bwz Gene: dapF (Haemophilus influenzae) Activity: Diaminopimelate epimerase, with EC number 5.1.1.7 Resources: FirstGlance, OCA, RCSB, PDBsum Function [DAPF_HAEIN] Catalyzes the stereoinversion of LL-2,6-diaminoheptanedioate (L,L-DAP) to meso-diaminoheptanedioate (meso-DAP), a precursor of L-lysine and an essential component of the bacterial peptidoglycan. Only accepts DAP isomers with the L configuration. 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 Diaminopimelate (DAP) epimerase catalyzes the stereoinversion of ll-DAP to meso-DAP, a precursor of l-lysine and an essential component of the bacterial peptidoglycan. This function is vital to bacteria and the enzyme therefore represents an attractive target for the design of novel anti-bacterials. DAP epimerase belongs to the group of PLP-independent amino acid racemases that function through a rather unusual mechanism involving two cysteines acting in concert as a base (thiolate) and an acid (thiol). We have solved the crystal structures of the apo-forms of DAP epimerase mutants (C73S and C217S) from Haemophilus influenzae at 2.3A and 2.2A resolution, respectively. These structures provide a snapshot of the enzyme in the first step of the catalytic cycle. Comparisons with the structures of the inhibitor-bound form reveal that the enzyme adopts an 'open conformation' in the absence of substrates or inhibitors with the two active site cysteines existing as a thiol-thiolate pair. Substrate binding to the C-terminal domain triggers the closure of the N-terminal domain coupled with tight encapsulation of the ligand, stabilization of the conformation of an active site loop containing Cys73 and expulsion of water molecules with concomitant desolvation of the thiolate base. This structural rearrangement is critical for catalysis. Dynamics of catalysis revealed from the crystal structures of mutants of diaminopimelate epimerase.,Pillai B, Cherney M, Diaper CM, Sutherland A, Blanchard JS, Vederas JC, James MN Biochem Biophys Res Commun. 2007 Nov 23;363(3):547-53. Epub 2007 Sep 17. PMID:17889830 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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