The binding of Cellulomonas fimi endoglucanase C (CenC) to cellulose and Sephadex is mediated by the N-terminal repeats.
Endoglucanase C (CenC) from Cellulomonas fimi binds to cellulose and to Sephadex. The enzyme has two contiguous 150-amino-acid repeats (N1 and N2) at its N-terminus and two unrelated contiguous 100-amino-acid repeats (C1 and C2) at its C-terminus. Polypeptides corresponding to N1, N1N2, C1, and C1C2 were produced by expression of appropriate cenC gene fragments in Escherichia coli. N1N2, but not N1 alone, binds to Sephadex; both polypeptides bind to Avicel, (a heterogeneous cellulose preparation containing both crystalline and non-crystalline components). Neither C1 nor C1C2 binds to Avicel or Sephadex. N1N2 and N1 bind to regenerated ('amorphous') cellulose but not to bacterial crystalline cellulose; the cellulose-binding domain of C. fimi exoglucanase Cex binds to both of these forms of cellulose. Amino acid sequence comparison reveals that N1 and N2 are distantly related to the cellulose-binding domains of Cex and C. fimi endoglucanases A and B.
Coutinho
J B
JB
Department of Microbiology, University of British Columbia, Vancouver, Canada.
Gilkes
N R
NR
Warren
R A
RA
Kilburn
D G
DG
Miller
R C
RC
D000192:Actinomycetales / Q000378:metabolism*; D000595:Amino Acid Sequence; D002480:Cellulase / Q000235:genetics / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism*; D003001:Cloning, Molecular; D003460:Crystallization; D003911:Dextrans / Q000378:metabolism*; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011485:Protein Binding; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid
D003911:Dextrans; D002482:Cellulose; C025614:sephadex; D004720:Endonucleases; D002480:Cellulase