title: Family A cellulases: two essential tryptophan residues in endoglucanase III from Trichoderma reesei.
abstract: Three tryptophan residues are readily oxidised by N-bromosuccinimide in endoglucanase III from Trichoderma reesei. Evidence was obtained that the residue first modified is situated in the cellulose-binding domain and the second in the enzyme's catalytic site. The latter influences the binding and hydrolysis of soluble substrates. The modification of a third residue does not further affect the catalytic properties. The present results complement published data concerning other identified catalytic residues, and help to clarify the active site structure of family A cellulases.
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001665:Binding Sites; D001974:Bromosuccinimide / Q000737:chemistry; D002384:Catalysis; D002480:Cellulase / Q000737:chemistry* / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D013329:Structure-Activity Relationship; D014242:Trichoderma / Q000201:enzymology*; D014364:Tryptophan / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D014364:Tryptophan; D002482:Cellulose; D002480:Cellulase; C061269:cel-3 protein, Fibrobacter succinogenes; D001974:Bromosuccinimide