Site-directed mutagenesis of the putative catalytic residues of Trichoderma reesei cellobiohydrolase I and endoglucanase I.
Site directed mutagenesis has been performed to test hypotheses concerning the putative active sites of Trichoderma reesei cellobiohydrolase I and endoglucanase I. It is shown that mutagenesis of the residue E126, previously proposed to be the proton donor in CBHI, did not totally inactivate the enzyme while mutagenesis of the residue E127 in the homologous enzyme EGI resulted in complete loss of activity. These results are compared with those obtained in similar studies of other glucanases and the effects on enzymatic activity of hyperglycosylation of the yeast produced cellulases are discussed.
Mitsuishi
Y
Y
VTT Biotechnical Laboratory, Espoo, Finland.
Nitisinprasert
S
S
Saloheimo
M
M
Biese
I
I
Reinikainen
T
T
Claeyssens
M
M
Keränen
S
S
Knowles
J K
JK
Teeri
T T
TT
D002384:Catalysis; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism; D043366:Cellulose 1,4-beta-Cellobiosidase; D002850:Chromatography, Gel; D004252:DNA Mutational Analysis; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism; D006031:Glycosylation; D008970:Molecular Weight; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D014242:Trichoderma / Q000201:enzymology* / Q000235:genetics
D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; C056374:endoglucanase 1; D002480:Cellulase; D043366:Cellulose 1,4-beta-Cellobiosidase