title: Primary structure, sequence analysis, and expression of the thermostable D-hydantoinase from Bacillus stearothermophilus SD1.
abstract: The gene coding for the thermostable D-hydantoinase from the thermophilic bacterium Bacillus stearothermophilus SD1 was cloned and its nucleotide sequence was completely determined. The D-hydantoinase protein showed considerable amino acid sequence homology (20-28%) with other hydantoinases and functionally related allantoinases and dihydroorotases. Strikingly the sequence of the enzyme from B. stearothermophilus SD1 exhibited greater than 89% identity with hydantoinases from thermophilic bacteria. Despite the extremely high amino acid homology among the hydantoinases from thermophiles, the C-terminal regions of the enzymes were completely different in both sequence and predicted secondary structure, implying that the C-terminal region plays an important role in determining the biochemical properties of the enzymes. Alignment of the sequence of the D-hydantoinase from B. stearothermophilus SD1 with those of other functionally related enzymes revealed four conserved regions, and five histidines and an acidic residue were found to be conserved, suggesting a close evolutionary relationship between all these enzymes.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Sciences and Technology, Kusong-dong Yusong-gu, Taejon, Korea. hskim@esorak.kaist.ac.kr
authors.forename: G J
authors.initials: GJ
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Park
authors.forename: D C
authors.initials: DC
authors.lastname: Lee
authors.forename: H S
authors.initials: HS
authors.lastname: Ro
authors.forename: H S
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000581:Amidohydrolases / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics; D001411:Geobacillus stearothermophilus / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid
chemical_list: D011994:Recombinant Proteins; D000581:Amidohydrolases; C020047:dihydropyrimidinase