1nfg

From Proteopedia

---

Revision as of 20:05, 20 November 2007

proteopedia linkproteopedia link

spinqualitylabelsall models 1nfg, resolution 2.7Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Structure of D-hydantoinase

Overview

D-Hydantoinase (D-HYD) is an industrial enzyme that is widely used in the, production of D-amino acids which are precursors for semisynthesis of, antibiotics, peptides, and pesticides. This report describes the crystal, structure of D-hydantoinase from Burkholderia pickettii (HYD(Bp)) at a, 2.7-A resolution. The structure of HYD(Bp) consists of a core, (alpha/beta)(8) triose phosphate isomerase barrel fold and a beta-sheet, domain, and the catalytic active site consists of two metal ions and six, highly conserved amino acid residues. Although HYD(Bp) shares only, moderate sequence similarity with D-HYDs from Thermus sp. (HYD(Tsp)) and, Bacillus stearothermophilus (HYD(Bst)), whose structures have recently, been solved, the overall structure and the structure of the catalytic, active site are strikingly similar. Nevertheless, the amino acids that, compose the substrate-binding site are less conserved and have different, properties, which might dictate the substrate specificity. Structural, comparison has revealed insights into the molecular basis of the, differential thermostability of D-HYDs. The more thermostable HYD(Tsp), contains more aromatic residues in the interior of the structure than, HYD(Bp) and HYD(Bst). Changes of large aromatic residues in HYD(Tsp) to, smaller residues in HYD(Bp) or HYD(Bst) decrease the hydrophobicity and, create cavities inside the structure. HYD(Tsp) has more salt bridges and, hydrogen-bonding interactions and less oxidation susceptible Met and Cys, residues on the protein surface than HYD(Bp) and HYD(Bst). Besides, HYD(Tsp) also contains more rigid Pro residues. These factors are likely, to make major contributions to the varying thermostability of these, enzymes. This information could be exploited in helping to engineer more, thermostable mesophilic enzymes.

About this Structure

1NFG is a Single protein structure of sequence from Ralstonia pickettii with ZN as ligand. Active as Dihydropyrimidinase, with EC number 3.5.2.2 Full crystallographic information is available from OCA.

Reference

Crystal structure of D-Hydantoinase from Burkholderia pickettii at a resolution of 2.7 Angstroms: insights into the molecular basis of enzyme thermostability., Xu Z, Liu Y, Yang Y, Jiang W, Arnold E, Ding J, J Bacteriol. 2003 Jul;185(14):4038-49. PMID:12837777

Page seeded by OCA on Tue Nov 20 22:12:44 2007