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Crystal structure of the probable haloacid dehalogenase PH0459 from Pyrococcus horikoshii OT3
Author(s) -
Arai Ryoichi,
KukimotoNiino Mutsuko,
Kuroishi Chizu,
Bessho Yoshitaka,
Shirouzu Mikako,
Yokoyama Shigeyuki
Publication year - 2006
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.051922406
Subject(s) - pyrococcus horikoshii , crystallography , crystal structure , stereochemistry , protein data bank (rcsb pdb) , hydrolase , monomer , chemistry , protein structure , biochemistry , enzyme , organic chemistry , polymer
PH0459, from the hyperthermophilic archaeon Pyrococcus horikoshii OT3, is a probable haloacid dehalogenase with a molecular mass of 26,725 Da. Here, we report the 2.0 Å crystal structure of PH0459 (PDB ID: 1X42) determined by the multiwavelength anomalous dispersion method. The core domain has an α/β structure formed by a six‐stranded parallel β‐sheet flanked by six α‐helices and three 3 10 ‐helices. One disulfide bond, Cys186–Cys212, forms a bridge between an α‐helix and a 3 10 ‐helix, although PH0459 seems to be an intracellular protein. The subdomain inserted into the core domain has a four‐helix bundle structure. The crystal packing suggests that PH0459 exists as a monomer. A structural homology search revealed that PH0459 resembles the l ‐2‐haloacid dehalogenases l ‐DEX YL from Pseudomonas sp. YL and DhlB from Xanthobacter autotrophicus GJ10. A comparison of the active sites suggested that PH0459 probably has haloacid dehalogenase activity, but its substrate specificity may be different. In addition, the disulfide bond in PH0459 probably facilitates the structural stabilization of the neighboring region in the monomeric form, although the corresponding regions in l ‐DEX YL and DhlB may be stabilized by dimerization. Since heat‐stable dehalogenases can be used for the detoxification of halogenated aliphatic compounds, PH0459 will be a useful target for biotechnological research.