1ZMT

Structure of haloalcohol dehalogenase HheC of Agrobacterium radiobacter AD1 in complex with (R)-para-nitro styrene oxide, with a water molecule in the halide-binding site

1ZMT の概要

• エントリーDOI: 10.2210/pdb1zmt/pdb
• 関連するPDBエントリー: 1ZMO 1ZO8
• 分子名称: Haloalcohol dehalogenase HheC, (R)-PARA-NITROSTYRENE OXIDE (3 entities in total)
• 機能のキーワード: haloalcohol dehalogenase, halohydrin dehalogenase, epoxide catalysis, enantioselectivity, lyase
• 由来する生物種: Agrobacterium tumefaciens
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 112579.25

構造登録者

de Jong, R.M.,Tiesinga, J.J.W.,Villa, A.,Tang, L.,Janssen, D.B.,Dijkstra, B.W. (登録日: 2005-05-10, 公開日: 2005-10-04, 最終更新日: 2024-02-14)

主引用文献

de Jong, R.M.,Tiesinga, J.J.W.,Villa, A.,Tang, L.,Janssen, D.B.,Dijkstra, B.W.
Structural Basis for the Enantioselectivity of an Epoxide Ring Opening Reaction Catalyzed by Halo Alcohol Dehalogenase HheC.
J.Am.Chem.Soc., 127:13338-13343, 2005

PubMed Abstract: Halo alcohol dehalogenase HheC catalyzes the highly enantioselective dehalogenation of vicinal halo alcohols to epoxides, as well as the reverse reaction, the enantioselective and beta-regioselective nucleophilic ring opening of epoxides by pseudo-halides such as azide and cyanide. To investigate this latter reaction, we determined X-ray structures of complexes of HheC with the favored and unfavored enantiomers of para-nitrostyrene oxide. The aromatic parts of the two enantiomers bind in a very similar way, but the epoxide ring of the unfavored (S)-enantiomer binds in a nonproductive inverted manner, with the epoxide oxygen and Cbeta atom positions interchanged with respect to those of the favored (R)-enantiomer. The calculated difference in relative Gibbs binding energy is in agreement with the observed loss of a single hydrogen bond in the S bound state with respect to the R bound state. Our results indicate that it is the nonproductive binding of the unfavored (S)-enantiomer, rather than the difference in affinity for the two enantiomers, that allows HheC to catalyze the azide-mediated ring opening of para-nitrostyrene oxide with high enantioselectivity. This work represents a rare opportunity to explain the enantioselectivity of an enzymatic reaction by comparison of crystallographic data on the binding of both the favored and unfavored enantiomers.

PubMed: 16173767
DOI: 10.1021/ja0531733

実験手法

X-RAY DIFFRACTION (1.7 Å)