2ggi | pdb_00002ggi

The mutant E149C-A182C of Deinococcus Radiodurans N-acylamino acid racemase

spinqualitylabelsall models 2ggi, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ggi is a 4 chain structure with sequence from Deinococcus radiodurans. This structure supersedes the now removed PDB entries 2fks and 2ba7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.2Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function NSAR_DEIRA Acts as a N-succinylamino acid racemase (NSAR) that catalyzes the racemization of N-succinyl-L-phenylglycine and N-succinyl-D/L-phenylalanine (PubMed:24872444, PubMed:25875730). Can catalyze the racemization of a broad range of N-acylamino acids, including N-acetyl-D/L-methionine, N-acetyl-D/L-phenylalanine, N-acetyl-L-glutamine, N-acetyl-L-tryptophan, N-acetyl-L-leucine, N-formyl-D-methionine, N-formyl-D-norleucine, N-carbamoyl-D-methionine and N-carbamoyl-D-norleucine (PubMed:15313614, PubMed:16650857, PubMed:25875730). Also converts 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC) to 2-succinylbenzoate (OSB) (PubMed:24872444). Catalyzes both N-succinylamino acid racemization and OSB synthesis at equivalent rates (PubMed:24872444). However, NSAR activity is probably the protein's biological function, because menaquinone biosynthesis genes are missing in this species (Probable). 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 N-Acylamino acid racemase (NAAAR) and N-carbamoyl-D-amino-acid amidohydrolase (D-NCAase) are important biocatalysts for producing enantiopure alpha-amino acids. NAAAR forms an octameric assembly and displays induced fit movements upon substrate binding, while D-NCAase is a tetramer that does not change conformation in the presence of a ligand. To investigate the effects of introducing potentially stabilizing S-S bridges in these different multimeric enzymes, cysteine residues predicted to form inter or intra-subunit disulfide bonds were introduced by site-directed mutagenesis. Inter-subunit S-S bonds were formed in two NAAAR variants (A68C-D72C and P60C-Y100C) and two d-NCAase variants (A302C and P295C-F304C). Intra-subunit S-S bonds were formed in two additional NAAAR variants (E149C-A182C and V265C). Crystal structures of NAAARs variants show limited deviations from the wild-type overall tertiary structure. An apo A68C-D72C subunit differs from the wild-type enzyme, in which it has an ordered lid loop, resembling ligand-bound NAAAR. The structures of A222C and A302C D-NCAases are nearly identical to the wild-type enzyme. All mutants with inter-subunit bridges had increases in thermostability. Compared with the wild-type enzyme, A68C-D72C NAAAR showed similar kcat/Km ratios, whereas mutant D-NCAases demonstrated increased kcat/Km ratios at high temperatures (A302C: 4.2-fold at 65 degrees C). Furthermore, molecular dynamic simulations reveal that A302C substantially sustains the fine-tuned catalytic site as temperature increases, achieving enhanced activity. Structure-stability-activity relationship in covalently cross-linked N-carbamoyl D-amino acid amidohydrolase and N-acylamino acid racemase.,Chiu WC, You JY, Liu JS, Hsu SK, Hsu WH, Shih CH, Hwang JK, Wang WC J Mol Biol. 2006 Jun 9;359(3):741-53. Epub 2006 Apr 18. PMID:16650857 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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