好熱性放線菌Thermoactinomyces vulgarisの2種類のプルラン分解α-アミラーゼの立体構造と機能  [in Japanese] Crystal Structures and Functions of Two Pullulan-hydrolyzing α-Amylases from a Thermophilic Actinomycete, Thermoactinomyces vulgaris  [in Japanese]

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Author(s)

    • 殿塚 隆史 TONOZUKA Takashi
    • 東京農工大学農学部応用生物科学科 Department of Applied Biological Science, Tokyo University of Agriculture and Technology
    • 神鳥 成弘 KAMITORI Shigehiro
    • 東京農工大学工学部生命工学科 Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology
    • 坂野 好幸 SAKANO Yoshiyuki
    • 東京農工大学農学部応用生物科学科 Department of Applied Biological Science, Tokyo University of Agriculture and Technology

Abstract

Themoactinomyces vulgaris R-47 produces two a-amylases, TVA I and TVA II, both of which hydrolyze pullulan and cyclodextrins. Site-directed mutagenic and X-ray crystallographic studies ofboth enzymes were carried out. The putative catalytic residues, Asp325, G1u354, and Asp421 of TVA II were modified. The mutated enzymes retained a trace of activity, less than 0.01% of the wild-type enzyme, and the action pattern of D421N enzyme was different from wild-type and othermutated TVA II. The crystal structures of the mutated TVA II complexed with β-cyclodextrin were determined. TVA II has domains A, B and C, like other a-amylases, and also has domain N, which is not commonly found in α-amylase family enzymes. A β-cyclodextrin was bound to domain A, and was also located close to domain B. Crystals of TVA I were obtained by the vapor diffusion method in the presence of polyethylene glycol. Like TVA II, TVA Iwas composed of domain N, A, B, and C. Comparing the domains of TVA I and TVA II, the structure and position of domain N were the most different. To investigate the roles of domain N further, domains N of TVA I and TVA II were truncated, and the activities of these enzymes were drastically decreased.

Journal

  • Journal of Applied Glycoscience

    Journal of Applied Glycoscience 48(2), 163-169, 2001-04-01

    The Japanese Society of Applied Glycoscience

References:  18

Codes

  • NII Article ID (NAID)
    10008252623
  • NII NACSIS-CAT ID (NCID)
    AN10453916
  • Text Lang
    JPN
  • Article Type
    REV
  • ISSN
    13403494
  • NDL Article ID
    5764620
  • NDL Source Classification
    ZP24(科学技術--化学・化学工業--糖・澱粉)
  • NDL Call No.
    Z17-15
  • Data Source
    CJP  NDL  J-STAGE 
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