Structural characterization of l-glutamate oxidase from Streptomyces sp. X-119-6

Jiro Arima, Chiduko Sasaki, Chika Sakaguchi, Hiroshi Mizuno, Takashi Tamura, Akiko Kashima, Hitoshi Kusakabe, Shigetoshi Sugio, Kenji Inagaki

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

l-Glutamate oxidase (LGOX) from Streptomyces sp. X-119-6, which catalyzes the oxidative deamination of l-glutamate, has attracted increasing attention as a component of amperometric l-glutamate sensors used in the food industry and clinical biochemistry. The precursor of LGOX, which has a homodimeric structure, is less active than the mature enzyme with an α2β 2γ2 structure; enzymatic proteolysis of the precursor forms the stable mature enzyme. We solved the crystal structure of mature LGOX using molecular replacement with a structurally homologous model of l-amino acid oxidase (LAAO) from snake venom: LGOX has a deeply buried active site and two entrances from the surface of the protein into the active site. Comparison of the LGOX structure with that of LAAO revealed that LGOX has three regions that are absent from the LAAO structure, one of which is involved in the formation of the entrance. Furthermore, the arrangement of the residues composing the active site differs between LGOX and LAAO, and the active site of LGOX is narrower than that of LAAO. Results of the comparative analyses described herein raise the possibility that such a unique structure of LGOX is associated with its substrate specificity.

Original languageEnglish
Pages (from-to)3894-3903
Number of pages10
JournalFEBS Journal
Volume276
Issue number14
DOIs
Publication statusPublished - Jul 2009

Keywords

  • L-amino acid oxidase
  • L-glutamate oxidase
  • Streptomyces
  • Substrate specificity
  • X-ray crystallographic structure

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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    Arima, J., Sasaki, C., Sakaguchi, C., Mizuno, H., Tamura, T., Kashima, A., Kusakabe, H., Sugio, S., & Inagaki, K. (2009). Structural characterization of l-glutamate oxidase from Streptomyces sp. X-119-6. FEBS Journal, 276(14), 3894-3903. https://doi.org/10.1111/j.1742-4658.2009.07103.x