Specificity mapping of cellulolytic enzymes: Classification into families of structurally related proteins confirmed by biochemical analysis

The specificities of 15 cellulolytic enzymes have been examined using chromophoric glycosides derived from d‐glucose, cellobiose, higher cellooligosaccharides, lactose, d‐xylose, and β‐(1,4)‐xylobiose. Coinciding with a classification based on hydrophobic cluster analysis of amino acid sequences, six families each showing a characteristic specificity pattern were observed. Furthermore, in these cases where the anomeric forms of reaction products were determined, results seem to indicate conservation of intrinsic reaction mechanism (single or double displacement) within each family. On the other hand, the low molecular weight substrates do not discriminate exo‐ from endocellulases. This functional differentiation is speculated to originate from the presence, in exoenzymes, of a tunnel‐shaped active site formed by extra loops in their structure.

[1]  J. Knowles,et al.  Three-dimensional structure of cellobiohydrolase II from Trichoderma reesei. , 1990, Science.

[2]  M. Claeyssens,et al.  Transfer reactions catalysed by a fungal β-D-xylosidase: enzymic synthesis of phenyl β-D-xylobioside , 1966 .

[3]  J. Knowles,et al.  Stereochemical course of the action of the cellobioside hydrolases I and II of Trichoderma reesei , 1988 .

[4]  H. Tilbeurgh,et al.  Fluorogenic and chromogenic glycosides as substrates and ligands of carbohydrases , 1988 .

[5]  M J Sternberg,et al.  Analysis and prediction of the location of catalytic residues in enzymes. , 1988, Protein engineering.

[6]  B. Henrissat,et al.  Stereochemistry of the hydrolysis reaction catalyzed by endoglucanase Z from Erwinia chrysanthemi , 1992, FEBS letters.

[7]  R. Aebersold,et al.  Structural and functional relationships in two families of β‐1,4‐glycanases , 1991 .

[8]  E. Hehre,et al.  Stereochemical course of hydrolysis and hydration reactions catalysed by cellobiohydrolases I and II from Trichoderma reesei , 1990, FEBS letters.

[9]  H. van Tilbeurgh,et al.  Studies of the cellulolytic system of the filamentous fungus Trichoderma reesei QM 9414. Substrate specificity and transfer activity of endoglucanase I. , 1990, The Biochemical journal.

[10]  B. Henrissat,et al.  Domains in microbial beta-1, 4-glycanases: sequence conservation, function, and enzyme families. , 1991, Microbiological reviews.

[11]  P. Alzari,et al.  Three-dimensional structure of a thermostable bacterial cellulase , 1992, Nature.

[12]  M. Claeyssens,et al.  Chromatographic separation of cellulolytic enzymes , 1988 .

[13]  M. Sinnott,et al.  Catalytic mechanism of enzymic glycosyl transfer , 1990 .

[14]  S. Withers,et al.  Direct 1H n.m.r. determination of the stereochemical course of hydrolyses catalysed by glucanase components of the cellulase complex. , 1986, Biochemical and biophysical research communications.

[15]  S. Withers,et al.  Stereoselective hydrolysis catalyzed by related beta-1,4-glucanases and beta-1,4-xylanases. , 1992, The Journal of biological chemistry.

[16]  B Henrissat,et al.  Cellulase families revealed by hydrophobic cluster analysis. , 1989, Gene.

[17]  M. Claeyssens,et al.  Study of the mode of action and site-specificity of the endo-(1----4)-beta-D-glucanases of the fungus Penicillium pinophilum with normal, 1-3H-labelled, reduced and chromogenic cello-oligosaccharides. , 1990, Biochemical Journal.

[18]  P Béguin,et al.  Molecular biology of cellulose degradation. , 1990, Annual review of microbiology.

[19]  R. Franck The mechanism of β-glycosidases: A reassessment of some seminal papers , 1992 .

[20]  D. Kilburn,et al.  Unusual sequence organization in CenB, an inverting endoglucanase from Cellulomonas fimi , 1991, Journal of bacteriology.

[21]  J. Mornon,et al.  Hydrophobic cluster analysis: An efficient new way to compare and analyse amino acid sequences , 1987, FEBS letters.

[22]  A. Lesk,et al.  The relation between the divergence of sequence and structure in proteins. , 1986, The EMBO journal.

[23]  O. Grépinet,et al.  Nucleotide sequence and deletion analysis of the xylanase gene (xynZ) of Clostridium thermocellum , 1988, Journal of bacteriology.

[24]  D. Wilson,et al.  Biochemistry and genetics of actinomycete cellulases. , 1992, Critical reviews in biotechnology.