Cellobiohydrolase A (CbhA) from the cellulolytic bacterium Cellulomonas fimi is a beta-1,4-exocellobiohydrolase analogous to Trichoderma reesei CBH II.
The gene cbhA from the cellulolytic bacterium Cellulomonas fimi encodes a protein of 872 amino acids designated cellobiohydrolase A (CbhA). Mature CbhA contains 832 amino acid residues and has a predicted molecular mass of 85,349 Da. It is composed of five domains: an N-terminal catalytic domain, three repeated sequences of 95 amino acids, and a C-terminal cellulose-binding domain typical of other C. fimi glycanases. The structure and enzymatic activities of the CbhA catalytic domain are closely related to those of CBH II, an exocellobiohydrolase in the glycosyl hydrolase family B from the fungus Trichoderma reesei. CbhA is the first such enzyme to be characterized in bacteria. The data support the proposal that extended loops around the active site distinguish exohydrolases from endohydrolases in this enzyme family.
Meinke
A
A
Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada.
Gilkes
N R
NR
Kwan
E
E
Kilburn
D G
DG
Warren
R A
RA
Miller
R C
RC
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002482:Cellulose / Q000378:metabolism; D043366:Cellulose 1,4-beta-Cellobiosidase; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism*; D006093:Gram-Positive Asporogenous Rods / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014242:Trichoderma / Q000201:enzymology
D011994:Recombinant Proteins; D002482:Cellulose; D006026:Glycoside Hydrolases; D043366:Cellulose 1,4-beta-Cellobiosidase