title: Crystal structure of dihydropyrimidinase from Pseudomonas aeruginosa PAO1: Insights into the molecular basis of formation of a dimer.
abstract: Dihydropyrimidinase, a tetrameric metalloenzyme, is a member of the cyclic amidohydrolase family, which also includes allantoinase, dihydroorotase, hydantoinase, and imidase. In this paper, we report the crystal structure of dihydropyrimidinase from Pseudomonas aeruginosa PAO1 at 2.1 Å resolution. The structure of P. aeruginosa dihydropyrimidinase reveals a classic (β/α)8-barrel structure core embedding the catalytic dimetal center and a β-sandwich domain, which is commonly found in the architecture of dihydropyrimidinases. In contrast to all dihydropyrimidinases, P. aeruginosa dihydropyrimidinase forms a dimer, rather than a tetramer, both in the crystalline state and in the solution. Basing on sequence analysis and structural comparison of the C-terminal region and the dimer-dimer interface between P. aeruginosa dihydropyrimidinase and Thermus sp. dihydropyrimidinase, we propose a working model to explain why this enzyme cannot be a tetramer.
authors: School of Biomedical Sciences, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Rd., Taichung City, Taiwan.
authors: Ching-Ting
authors: CT
authors: Tzeng
authors: School of Biomedical Sciences, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Rd., Taichung City, Taiwan.
authors: Yen-Hua
authors: YH
authors: Huang
authors: School of Biomedical Sciences, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Rd., Taichung City, Taiwan; Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Sec. 1, Chien-Kuo N. Rd., Taichung City, Taiwan. Electronic address: cyhuang@csmu.edu.tw.
authors: Cheng-Yang
authors: CY
authors: Huang
mesh_terms: D000581:Amidohydrolases / Q000737:chemistry*; D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D055503:Protein Multimerization; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D012492:Salts / Q000737:chemistry; D012996:Solutions; D013824:Thermus / Q000201:enzymology
chemical_list: D012492:Salts; D012996:Solutions; D000581:Amidohydrolases; C020047:dihydropyrimidinase
keywords: Allantoinase; Dihydroorotase; Dihydropyrimidinase; Dimer; Hydantoinase; Imidase