Kinetic characterization of CYO1, a cotyledon-specific chloroplast biogenesis factor of Arabidopsis, had thiol-disulfide reduction activity.

DOI

Bibliographic Information

Other Title
  • シロイヌナズナ子葉特異的葉緑体形成因子CYO1の酵素学的解析

Abstract

Chloroplast development in cotyledons differs in a number of ways from that in true leaves, but the cotyledon-specific program of chloroplast biogenesis has not been clarified. The cyo1 mutant in Arabidopsis thaliana has albino cotyledons but normal green true leaves. Chloroplasts develop abnormally in cyo1 mutant plants grown in the light, but etioplasts are normal in mutants grown in the dark. CYO1 has a C4-type zinc finger domain similar to that of Escherichia coli DnaJ. Recombinant CYO1 accelerates disulfide bond reduction in the model substrate insulin and renatures RNase A, indicating that CYO1 has protein disulfide isomerase activity. In this study, we analyzed the kinetics of CYO1 in detail. The optimum temperature and pH of CYO1 were 40˚C and pH 6.7, respectively. Since the [S]-[V] plot was sigmoid, CYO1 should be an allosteric enzyme. To determine the amino acids important for CYO1 activity, we generated a series of 7 point mutations of cysteine residues in CYO1, and report these results.

Journal

Details 詳細情報について

  • CRID
    1390001205631453056
  • NII Article ID
    130006992660
  • DOI
    10.14841/jspp.2010.0.0833.0
  • Data Source
    • JaLC
    • CiNii Articles
  • Abstract License Flag
    Disallowed

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