Patent ID: 8110389

Claim:
An isolated modified Trichoderma reesei Family 6 (TrCel6A) cellulase comprising one or more amino acid substitutions selected from the group consisting of: substitution of a basic amino acid at position 129 by a charge-neutral or an acidic amino acid; substitution of a charge neutral amino acid at one or more of positions 322 and 363 by an acidic amino acid; and substitution of an amino acid at position 186 by a threonine; wherein amino acids 83-447 of the modified TrCel6A are from about 90% to about 99% identical to amino acids 83-447 of SEQ ID NO: 1 and wherein the modified TrCel6A cellulase exhibits at least a 15% reduction in the extent of deactivation by lignin relative to that of a parental TrCel6A cellulase.