Key amino acid residues for the endo‐processive activity of GH74 xyloglucanase. Issue 9 (19th March 2014)

• Record Type: Journal Article
• Authors: Matsuzawa, Tomohiko; Saito, Yuji; Yaoi, Katsuro
• Is Part Of: FEBS letters. Volume 588:Issue 9(2014)
• Page Start: 1731
• Page End: 1738
• Publication Date: 2014-03-19
• Subjects: Xyloglucanase -- Xyloglucan -- Endo-processive -- Glucanase -- Hemicellulose; Biochemistry -- Periodicals; Biophysics -- Periodicals; Molecular biology -- Periodicals; Biochimie -- Périodiques; Biochemistry; Biophysics; Molecular biology; Periodicals; 572.05
• DOI: 10.1016/j.febslet.2014.03.023
• Languages: English
• ISSNs: 0014-5793

Abstract

Abstract : Unlike endo‐dissociative‐xyloglucanases, Paenibacillus XEG74 is an endo‐processive xyloglucanase that contains four unique tryptophan residues in the negative subsites (W61 and W64) and the positive subsites (W318 and W319), as indicated by three‐dimensional homology modelling. Selective replacement of the positive subsite residues with alanine mutations reduced the degree of processive activity and resulted in the more endo‐dissociative‐activity. The results showed that W318 and W319, which are found in the positive subsites, are essential for processive degradation and are responsible for maintaining binding interactions with xyloglucan polysaccharide through a stacking effect. Abstract : Paenibacillus XEG74 contains four Trp residues in positive and negative subsites. The positive subsite residues, W318 and W319, are essential for processive activity. W318 and W319 may be responsible for maintaining the binding of substrate.