Catalytic Thiol and Carboxylate: Role of Cysteine and Glutamic Acid in the Xylosidic Activity of Endoxylanase from Chainia sp. (NCL 82-5-1)
Authors: Subray S.H.1; Ameeta R.K.2; Krishna N.G.2; Khan I.M.1
Source: Archives of Biochemistry and Biophysics, Volume 355, Number 2, July 1998 , pp. 153-159(7)
Publisher: Academic Press
Abstract:
Chemical modification of the endoxylanase from Chainia sp. with group-specific chemical modifiers in the absence and presence of substrate and kinetics of modification revealed the involvement of a thiol and a carboxylate in the catalytic function of the enzyme. The active-site peptides were chemically labeled and sequenced. The sequence alignment of the chemically labeled peptide with other family G11 xylanases showed that the catalytic glutamate of Chainia xylanase is located in a highly homologous region and may function as an acidbase catalyst while thiol of the Cys may function as a nucleophile. Copyright 1998 Academic Press.
Language: English
Document Type: Research article
Affiliations: 1: Division of Biochemical Sciences 2: Division of Biochemical Sciences, Division of Organic Chemistry (S), National Chemical Laboratory, Pune, 411 008, India

Click here for Page Help