1w62 | pdb_00001w62

PROLINE RACEMASE IN COMPLEX WITH ONE MOLECULE OF PYRROLE-2-CARBOXYLIC ACID (HEMI FORM)

spinqualitylabelsall models 1w62, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1w62 is a 2 chain structure with sequence from Trypanosoma cruzi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: PYC Related: 1w61 Activity: Proline racemase, with EC number 5.1.1.4 Resources: FirstGlance, OCA, RCSB, PDBsum 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 Amino acid racemases catalyze the stereoinversion of the chiral C alpha to produce the d-enantiomers that participate in biological processes, such as cell wall construction in prokaryotes. Within this large protein family, bacterial proline racemases have been extensively studied as a model of enzymes acting with a pyridoxal-phosphate-independent mechanism. Here we report the crystal structure of the proline racemase from the human parasite Trypanosoma cruzi (TcPRACA), a secreted enzyme that triggers host B cell polyclonal activation, which prevents specific humoral immune responses and is crucial for parasite evasion and fate. The enzyme is a homodimer, with each monomer folded in two symmetric alpha/beta subunits separated by a deep crevice. The structure of TcPRACA in complex with a transition-state analog, pyrrole-2-carboxylic acid, reveals the presence of one reaction center per monomer, with two Cys residues optimally located to perform acid/base catalysis through a carbanion stabilization mechanism. Mutation of the catalytic Cys residues abolishes the enzymatic activity but preserves the mitogenic properties of the protein. In contrast, inhibitor binding promotes the closure of the interdomain crevice and completely abrogates B cell proliferation, suggesting that the mitogenic properties of TcPRACA depend on the exposure of transient epitopes in the ligand-free enzyme. Crystal structure, catalytic mechanism, and mitogenic properties of Trypanosoma cruzi proline racemase.,Buschiazzo A, Goytia M, Schaeffer F, Degrave W, Shepard W, Gregoire C, Chamond N, Cosson A, Berneman A, Coatnoan N, Alzari PM, Minoprio P Proc Natl Acad Sci U S A. 2006 Feb 7;103(6):1705-10. Epub 2006 Jan 30. PMID:16446443 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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