CBH1 homologs and variant CBH1 cellulases
Disclosed are a number of homologs and variants of Hypocrea jecorina Cel7A (formerly Trichoderma reesei cellobiohydrolase I or CBH1), nucleic acids encoding the same and methods for producing the same. The homologs and variant cellulases have the amino acid sequence of a glycosyl hydrolase of family 7A wherein one or more amino acid residues are substituted and/or deleted.
1. An isolated variant H. jecorina CBH1 cellulase, wherein said variant comprises a substitution or deletion at a position corresponding to T66 of the mature H. jecorina CBH1 protein (SEQ ID NO:2), wherein said variant H. jecorina CBH1 cellulase has cellulolytic activity and has at least 95% sequence identity to SEQ ID NO:2.
2. An isolated variant H. jecorina CBH1 cellulase according to claim 1 , wherein said variant further comprises a substitution at a position corresponding to a residue selected from the group consisting of Q186(E), S195(A/F), E239S, G242(H/Y/N/S/T/D/A) and P412(T/S/A).
3. An isolated variant H. jecorina CBH1 cellulase, wherein said variant consists of a substitution or deletion at a position corresponding to T66 of the mature H. jecorina CBH1 protein (SEQ ID NO:2), wherein said variant H. jecorina CBH1 cellulase has cellulolytic activity.
4. An isolated variant H. jecorina CBH1 cellulase, wherein said variant consists of a substitution or deletion at a position corresponding to T66 of the mature H. jecorina CBH1 protein (SEQ ID NO:2) and a substitution at a position corresponding to a residue selected from the group consisting of Q186(E), S195(A/F), E239S, G242(H/Y/N/S/T/D/A) and P412(T/S/A), wherein said variant H. jecorina CBH1 cellulase has cellulolytic activity.
5. An isolated variant H. jecorina CBH1 cellulase according to claim 1 , wherein said variant further comprises a substitution at a position corresponding to a residue selected from the group consisting of L6, P13, T24, Q27, S47, T59, G88, T160, Q186, S195, T232, E236, E239, G242, N250, T281, F311, N327, D329, A336, K354, V407, P412, T417 and F418.
6. An isolated variant H. jecorina CBH1 cellulase, wherein said variant consists of a substitution or deletion at a position corresponding to T66 of the mature H. jecorina CBH1 protein (SEQ ID NO:2) and a substitution at a position corresponding to a residue selected from the group consisting of L6, P13, T24, Q27, S47, T59, G88, T160, Q186, S195, T232, E236, E239, G242, N250, T281, F311, N327, D329, A336, K354, V407, P412, T417 and F418, wherein said variant H. jecorina CBH1 cellulase has cellulolytic activity.