Identification of an essential glutamate residue in the active site of endoglucanase III from Trichoderma reesei.
n-Propyl, n-butyl and n-pentyl beta-cellobiosides with a reactive omega-epoxide in their aglycon completely and irreversibly inactivate endoglucanase III from Trichoderma reesei. The pentyl derivative was found to be most effective. From these affinity labeling experiments evidence was found for the implication of Glu329 in the reaction mechanism. This is discussed in relation to other structural/functional data known for endoglucanase III and several other family A glycanases.
Macarron
R
R
Departamento de Bioquimica, Facultad de Ciencias Biologicas, Universidad Complutense, Madrid, Spain.
van Beeumen
J
J
Henrissat
B
B
de la Mata
I
I
Claeyssens
M
M
D000345:Affinity Labels; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001665:Binding Sites; D002475:Cellobiose / Q000031:analogs & derivatives; D002480:Cellulase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D005971:Glutamates / Q000032:analysis*; D018698:Glutamic Acid; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013379:Substrate Specificity; D014242:Trichoderma / Q000201:enzymology*
D000345:Affinity Labels; D001426:Bacterial Proteins; D005971:Glutamates; D002475:Cellobiose; D018698:Glutamic Acid; D002480:Cellulase; C061269:cel-3 protein, Fibrobacter succinogenes