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Study on Structure and Function of Vero Toxins (Shiga-like) Toxins Produced by EscherichiaDB coli

Research Project

Project/Area Number 01480174
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 細菌学
Research InstitutionKYOTO UNIVERSITY

Principal Investigator

TAKEDA Yoshifumi  Faculty of Medicine, Kyoto University, Professor, 医学部 (30029772)

Co-Investigator(Kenkyū-buntansha) NISHIBUCHI Mitsuaki  Faculty of Medicine, Kyoto University, Associate Professor, 医学部, 助教授 (50189304)
Project Period (FY) 1989 – 1990
Project Status Completed (Fiscal Year 1990)
Budget Amount *help
¥6,800,000 (Direct Cost: ¥6,800,000)
Fiscal Year 1990: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1989: ¥4,400,000 (Direct Cost: ¥4,400,000)
KeywordsVero toxin / Enterohemorrhagic E. coli / Inhibition of protein synthesis / RNA N-glycosidase / Site directed mutagenesis / 活性中心 / 腸管出血性大腸菌 / RNA N-グリコシダ-ゼ
Research Abstract

Enterohemorrhagic Escherichia coli causes infant diarrhea, hemorrhagic colitis and hemolytic uremic syndrome in man. Pathogenesis is considered to be closely related to Vero toxins produced by the organisms. It has been reported that both two types of Vero toxins (VT1 and VT2) show RNA N-glycosidase activity and cleave a glycosidic bond of adenosine at position 4324 from N-terminus of 28S ribosomal RNA of 60S ribosomal subunit of eukaryotic cells. This enzymatic activity results in the inhibition of EF-u dependent tRNA binding and thus the inhibition of protein synthesis. This mode of action to that of ricin.
Comparison of the primary structures of the A subunits of VT1, VT2 and the ricin A chain revealed three conserved regions (amino acid residues 51-55, 167-171 and 202-207 from the N-terminus of VT1). All three regions of the ricin A chain corresponded in position to the active site of ricin proposed by X-ray crystal diffraction analysis. To determine the relative importance of the conserved amino acid residues for toxin activity of VT1, we prepared VT1 mutants with single amino-acid substitutions by oligonucleotide-directed site-specific mutagenesis. Twenty-two mutants were prepared to examine 14 conserved residues and their cytotoxicities to Vero cells and inhibitory activities on protein synthesis in a rabbit reticulocyte lysate were compared with those of wild-type VT1. Replacement of glutamic acid at position 167 by glutamine and of arginine at position 170 by leucine reduced both activities drastically. These results suggest that glutamic acid at position 167 and arginine at position 170 play the important role in the toxin activity of VT1. A possibility of these mutant toxins to be protective antigen (s) to protect enterohemorrhagic E. Coli infection wil be further studied.

Report

(3 results)
  • 1990 Annual Research Report   Final Research Report Summary
  • 1989 Annual Research Report
  • Research Products

    (20 results)

All Other

All Publications (20 results)

  • [Publications] Yuichi Oku: "Purification and some properties of a Vero toxin from a human strain of OOEscherichiaWWーPP OOcoliWWーPP that is immunologically related to Shigaーlike toxin II(VT2)." Microbial Pathogenesis. 6. 113-122 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] 竹田 美文: "志賀毒素とVero毒素(志賀毒素様毒素):構造と作用機作" 臨床と微生物. 16. 67-75 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Hideaki Ito: "Cloning and nucleotide sequencing of Vero toxin 2 variant genes from OOEscherichiaWWーPP OOcoliWWーPP O91:H21 isolated from a patient with the hemolytic uremic syndrome." Microbial Pathogenesis. 8. 47-60 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masayuki Furutani: "Demonstration of RNA Nーglycosidase activity of a Vero toxin(VT2 variant)produced by OOEscherichiaWWーPP OOcoliWWーPP O91:H21 from a patient with the hemolytic uremic syndrome." Microbiology Immunology. 34. 387-392 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Hideaki Ito: "Analysis of the antigenic difference between Vero toxin 2(VT2)and VT£ variant(VT2)of Verotoxinーproducing OOEscherichiaWWーPP OOcoliWWーPP by a siteーdirected mutagenesis." FEMS Microbiology Letters.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] 田中 博: "Vero毒素産生性大腸菌(VTEC)の輸入食肉からの分離" 感染症学雑誌.

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Yuichi Oku: "Purification and some properties of a Vero toxin from a human strain Escherichia coli that is immunologically related to Shiga-like toxin II (VT2)." Microbial Pathogenesis. 6. 113-122 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Hideaki Ito: "Cloning and nucleotide sequencing of Vero toxin 2 variant genes from Escherichia coli O91 : H21 isolated from a patient with the hemolytic uremic syndrome." Microbial Pathogenesis. 8. 47-60 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Masayuki Furutani: "Demonstration of RNA N-glycosidase activity of a Vero toxin (VT2 variant) produced by Escherichia coli O91 : H21 from a patient with the hemolytic uremic syndrome." Microbiology Immunology. 34. 387-392 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Hideaki Ito: "Analysis of the antigenic difference between Vero toxin 2 (VT2) and VT2 variant (VT2) of Verotoxin-producing Escherichia coli by a site-directed mutagenesis." FEMS Microbiology Letters.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Shinji Yamasaki: "Importance of arginine at position 170 of the A subunit of Vero toxin 1 produced by enterohemorrhagic Escherichia coli for toxin activity." Microbial Pathogenesis.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1990 Final Research Report Summary
  • [Publications] Hideaki Ito: "Cloning and nucleotide sequencing of Vero toxin 2 variant genes from Escherichia coli 091:H21 isolated from a patient with the hemolytic uremic syndrome." Microbial Pathogenesis. 8. 47-60 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] Masayuki Furutani: "Demonstration of RNA Nーglycositase activity of a vero toxin (VT2 variant) produced by Escherichia coli 091:H21 from a papient with the hemolytic uremic syndrome." Microbiology Immunology. 34. 387-392 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] Hideaki Ito: "Analysis of the antigenic difference between Vero toxin 2 (VT2) and VT2 variant (VT2) of verotoxinーproducing Escherichia coli by a siteーdirected mutagenesis." FEMS Microbiology Letters.

    • Related Report
      1990 Annual Research Report
  • [Publications] Shinji Yamasaki: "Importance of arginine at position 170 of the A subunit of Vero toxin 1 produced by enterohemorrhagic Escherichia coli for toxin activity." Microbial Pathogenesis.

    • Related Report
      1990 Annual Research Report
  • [Publications] Yuichi Oku et al.: "Purification and some properties of a Vero toxin from a human strain of Escherichia coli that is immnologically related to Shiga-like toxin II(VT2)." Microbial pthogenesis. 6. 113-122 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] 田中博他: "Vero毒素産生性大腸菌0111:H^-による集団下痢症の細菌学的研究" 感染症学雑誌. 63. 1187-1194 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] 竹田美文: "志賀毒素とVero毒素(志賀毒素様毒素):構造と作用機作" 臨床と微生物. 16. 67-75 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Masayuki Furutani et al.: "Demonstration of RNA N-glycosidase activity of a Vero toxin(VT2 variant)produced by Escherichia coli 091:H21 from a patient with the hemolytic uremic syndome." Microbial pathogenesis.

    • Related Report
      1989 Annual Research Report
  • [Publications] Hedeaki Ito et al.: "Cloninq and nucleotide sequencing of Vero toxin 2 variant genes from Escherichia coli 091:H21 isolated from a patient with the hemolytic uremic syndrome." Microbial pathogenesis.

    • Related Report
      1989 Annual Research Report

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Published: 1989-04-01   Modified: 2016-04-21  

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