Tryptophan 272: an essential determinant of crystalline cellulose degradation by Trichoderma reesei cellobiohydrolase Cel6A

A Koivula, T Kinnari, Vesa Harjunpaa, L Ruohonen, A Teleman, T Drakenberg, J Rouvinen, TA Jones, TT Teeri*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Trichoderma reesei cellobiohydrolase Cel6A (formerly CBHII) has a tunnel shaped active site with four internal subsites for the glucose units. We have predicted an additional ring stacking interaction for a sixth glucose moiety with a tryptophan residue (W272) found on the domain surface. Mutagenesis of this residue selectively impairs the enzyme function on crystalline cellulose but not on soluble or amorphous substrates. Our data shows that W272 forms an additional subsite at the entrance of the active site tunnel and suggests it has a specialised role in crystalline cellulose degradation, possibly in guiding a glucan chain into the tunnel. (C) 1998 Federation of European Biochemical Societies.

Original languageEnglish
Pages (from-to)341-346
Number of pages6
JournalFEBS Letters
Volume429
Issue number3
Publication statusPublished - 16 Jun 1998
MoE publication typeA1 Journal article-refereed

Keywords

  • cellulase
  • crystalline cellulose
  • mutagenesis
  • oligosaccharide
  • sugar binding site
  • LIMITED PROTEOLYSIS
  • GLYCOSYL HYDROLASES
  • HYDROLYSIS
  • DOMAIN
  • CELLULASES
  • QM-9414
  • SITE

Cite this

Koivula, A., Kinnari, T., Harjunpaa, V., Ruohonen, L., Teleman, A., Drakenberg, T., Rouvinen, J., Jones, TA., & Teeri, TT. (1998). Tryptophan 272: an essential determinant of crystalline cellulose degradation by Trichoderma reesei cellobiohydrolase Cel6A. FEBS Letters, 429(3), 341-346.