Applied Microbiology and Biotechnology

, Volume 71, Issue 5, pp 654–660

Properties of cellulosomal family 9 cellulases from Clostridium cellulovorans

  • Takamitsu Arai
  • Akihiko Kosugi
  • Helen Chan
  • Roger Koukiekolo
  • Hideaki Yukawa
  • Masayuki Inui
  • Roy H. Doi
Biotechnologically Relevant Enzymes and Proteins

DOI: 10.1007/s00253-005-0249-6

Cite this article as:
Arai, T., Kosugi, A., Chan, H. et al. Appl Microbiol Biotechnol (2006) 71: 654. doi:10.1007/s00253-005-0249-6

Abstract

The cellulosomal family 9 cellulase genes engH, engK, engL, engM, and engY of Clostridium cellulovorans have been cloned and sequenced. We compared the enzyme activity of family 9 cellulosomal cellulases from C. cellulovorans and their derivatives. EngH has the highest activity toward soluble cellulose derivatives such as carboxymethylcellulose (CMC) as well as insoluble cellulose such as acid-swollen cellulose (ASC). EngK has high activity toward insoluble cellulose such as ASC and Avicel. The results of thin-layer chromatography showed that the cleavage products of family 9 cellulases were varied. These results indicated that family 9 endoglucanases possess different modes of attacking substrates and produce varied products. To investigate the functions of the carbohydrate-binding module (CBM) and the catalytic module, truncated derivatives of EngK, EngH, and EngY were constructed and characterized. EngHΔCBM and EngYΔCBM devoid of the CBM lost activity toward all substrates including CMC. EngKΔCBM and EngMΔCBM did not lose activity toward CMC but lost activity toward Avicel. These observations suggest that the CBM is extremely important not only because it mediates the binding of the enzyme to the substrates but also because it participates in the catalytic function of the enzyme or contributes to maintaining the correct tertiary structure of the family 9 catalytic module for expressing enzyme activity.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Takamitsu Arai
    • 1
  • Akihiko Kosugi
    • 2
  • Helen Chan
    • 1
  • Roger Koukiekolo
    • 3
  • Hideaki Yukawa
    • 4
  • Masayuki Inui
    • 4
  • Roy H. Doi
    • 1
  1. 1.Section of Molecular and Cellular BiologyUniversity of CaliforniaDavisUSA
  2. 2.Japan International Research Center for Agricultural Sciences (JIRCAS)TsukubaJapan
  3. 3.SIMS DepartmentOttawaCanada
  4. 4.Research Institute of Innovative Technology for the Earth (RITE)KyotoJapan

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