4lhd | pdb_00004lhd

Crystal structure of Synechocystis sp. PCC 6803 glycine decarboxylase (P-protein), holo form with pyridoxal-5'-phosphate and glycine, closed flexible loop

spinqualitylabelsall models 4lhd, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4lhd is a 2 chain structure with sequence from Syny3. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: BCT, EDO, GLY, PO4 NonStd Res: LLP Related: 4lgl, 4lhc Gene: gcvP, slr0293 (SYNY3) Activity: Glycine dehydrogenase (decarboxylating), with EC number 1.4.4.2 Resources: FirstGlance, OCA, RCSB, PDBsum Function [GCSP_SYNY3] The glycine cleavage system catalyzes the degradation of glycine. The P protein binds the alpha-amino group of glycine through its pyridoxal phosphate cofactor; CO(2) is released and the remaining methylamine moiety is then transferred to the lipoamide cofactor of the H protein (By similarity). Publication Abstract from PubMed Glycine decarboxylase, or P-protein, is a pyridoxal 5'-phosphate (PLP) dependent enzyme in one-carbon metabolism of all organisms, in the glycine and serine catabolism of vertebrates, and in the photorespiratory pathway of oxygenic phototrophs. P-protein from the cyanobacterium Synechocystis sp. PCC 6803 is an alpha2 homodimer with high homology to eukaryotic P-proteins. The crystal structure of the apo enzyme shows the C-terminus locked in a closed conformation by a disulphide bond between Cys972 in the C-terminus and Cys353 located in the active site. Presence of the disulphide bridge isolates the active site from solvent and hinders the binding of PLP and glycine in the active site. Variants produced by substitution of Cys972 and Cys353 by Ser using site-directed mutagenesis have distinctly lower specific activities supporting the crucial role of these highly conserved redox-sensitive amino acid residues for P-protein activity. Reduction of the 353-972 disulphide releases the C-terminus and allows access to the active site. PLP and the substrate glycine bind in the active site of this reduced enzyme and appear to cause further conformational changes involving a flexible surface loop. The observation of the disulphide bond that acts to stabilise the closed form suggests a molecular mechanism for the redox-dependent activation of glycine decarboxylase observed earlier. Structure of the Homodimeric Glycine Decarboxylase P-protein from Synechocystis sp. PCC 6803 Suggests a Mechanism for Redox-Regulation.,Hasse D, Andersson E, Carlsson G, Masloboy A, Hagemann M, Bauwe H, Andersson I J Biol Chem. 2013 Oct 11. PMID:24121504 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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