Stereochemical course of hydrolysis catalysed by Cellulomonas fimi CenE, a member of a new family of beta-1,4-glucanases

• Published in: Biochemical and biophysical research communications Vol. 199; no. 3; p. 1223
• Main Authors: Shen, H, Tomme, P, Meinke, A, Gilkes, N R, Kilburn, D G, Warren, R A, Miller, Jr, R C
• Format: Journal Article
• Language: English
• Published: United States 30-03-1994
• Subjects: Amino Acid Sequence; Carrier Proteins - biosynthesis; Carrier Proteins - isolation & purification; Carrier Proteins - metabolism; Cellulase - biosynthesis; Cellulase - isolation & purification; Cellulase - metabolism; Cellulose; Cloning, Molecular; Escherichia coli; Genes, Bacterial; Genomic Library; Hydrolysis; Molecular Sequence Data; Sequence Homology, Amino Acid; Substrate Specificity
• ISSN: 0006-291X
• DOI: 10.1006/bbrc.1994.1361

The gene for a previously identified, extracellular, 120 kDa cellulose-binding protein (Cbp120) was isolated from a Cellulomonas fimi genomic library and expressed in Escherichia coli. Qualitative analysis of CM-cellulose hydrolysis shows that Cbp120 is an endo-beta-1,4-glucanase. Cbp120, now renamed CenE, catalyzes hydrolysis of cellohexaose with inversion of anomeric carbon configuration, characteristic of a single displacement reaction. Partial sequencing of its gene shows that CenE has significant sequence similarity with the catalytic domains of five enzymes from cellulolytic bacteria. It is proposed that the six enzymes form a new family of beta-1,4-glucanases. CenE is the first enzyme from this family to be characterized stereochemically.