2FPS

Crystal structure of the N-terminal domain of E.coli HisB- Apo Ca model.

2FPS の概要

• エントリーDOI: 10.2210/pdb2fps/pdb
• 関連するPDBエントリー: 2FPR 2FPU 2FPW 2FPX
• 分子名称: Histidine biosynthesis bifunctional protein hisB, ZINC ION, CALCIUM ION, ... (5 entities in total)
• 機能のキーワード: histidinol phosphate phosphatase, hisb, bifunctional enzyme., structural genomics, bacterial structure genomics, montreal-kingston bacterial structural genomics initiative, bsgi, hydrolase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm : Q9S5G5
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 40415.34

構造登録者

Rangarajan, E.S.,Cygler, M.,Matte, A.,Montreal-Kingston Bacterial Structural Genomics Initiative (BSGI) (登録日: 2006-01-17, 公開日: 2006-09-05, 最終更新日: 2023-08-30)

主引用文献

Rangarajan, E.S.,Proteau, A.,Wagner, J.,Hung, M.N.,Matte, A.,Cygler, M.
Structural snapshots of Escherichia coli histidinol phosphate phosphatase along the reaction pathway.
J.Biol.Chem., 281:37930-37941, 2006

PubMed Abstract: HisB from Escherichia coli is a bifunctional enzyme catalyzing the sixth and eighth steps of l-histidine biosynthesis. The N-terminal domain (HisB-N) possesses histidinol phosphate phosphatase activity, and its crystal structure shows a single domain with fold similarity to the haloacid dehalogenase (HAD) enzyme family. HisB-N forms dimers in the crystal and in solution. The structure shows the presence of a structural Zn(2+) ion stabilizing the conformation of an extended loop. Two metal binding sites were also identified in the active site. Their presence was further confirmed by isothermal titration calorimetry. HisB-N is active in the presence of Mg(2+), Mn(2+), Co(2+), or Zn(2+), but Ca(2+) has an inhibitory effect. We have determined structures of several intermediate states corresponding to snapshots along the reaction pathway, including that of the phosphoaspartate intermediate. A catalytic mechanism, different from that described for other HAD enzymes, is proposed requiring the presence of the second metal ion not found in the active sites of previously characterized HAD enzymes, to complete the second half-reaction. The proposed mechanism is reminiscent of two-Mg(2+) ion catalysis utilized by DNA and RNA polymerases and many nucleases. The structure also provides an explanation for the inhibitory effect of Ca(2+).

PubMed: 16966333
DOI: 10.1074/jbc.M604916200

実験手法

X-RAY DIFFRACTION (2.2 Å)