Novel variant hypocrea jecorina cbh1 cellulase

Abstract

Described herein are variants of H. jecorina CBH I, a Cel7 enzyme. The present invention provides novel cellobiohydrolases that have improved thermostability and reversibility.

1 - 23 . (canceled) 
     
     
         24 . A nucleic acid encoding a  Hypocrea jecorina  CBH I variant consisting essentially of an amino acid sequence having at least 96.4% sequence identity to the amino acid sequence of SEQ ID NO:2, having CBH I cellulase activity, and comprising one or more amino acid substitutions selected from the group consisting of Q17L, G22D, T41I, N49S, S57N, A68T, A77D, S92T, N103I, A112E, S113(T/N/D), E193V, S196T, M213I, P227(L/T/A), T246(C/A), D249K, Y252(A/Q), T255P, D257E, D259W, S278P, S279N, K286M, L288F, E295K, T296P, S297T, N301(R/K), E325K, T332(K/Y/H), F338Y, S342Y, F352L, T356L, Y371C, T380G, Y381D, V393G, S398T, V403D, S411F, G430F, G440R, T462I, T484S, Q487L, and P491L. 
     
     
         25 . The nucleic acid of claim  64 , wherein the CBH1 variant comprises one or more amino acid substitutions selected from the group consisting of N49S, A68T, A77D, S92T, S113(N/D), P227(A/L/T), D249K, T255P, D257E, S279N, L288F, E295K, S297T, N301(R/K), T332(K/Y/H), F338Y, T356L, V393G, and G430F. 
     
     
         26 . A vector comprising a nucleic acid of  claim 24 . 
     
     
         27 . A host cell transformed with the vector of  claim 26 . 
     
     
         28 . A method of producing a CBH I variant comprising the steps of:
 (a) culturing the host cell according to  claim 27  in a suitable culture medium under suitable conditions to produce a CBH I variant; and   (b) obtaining said produced CBH I variant.   
     
     
         29 . A recombinant filamentous fungal cell engineered to be capable of expressing a CBH I variant encoded by the nucleic acid of  claim 24 . 
     
     
         30 . A method of producing a CBH I variant comprising the steps of:
 (a) culturing the recombinant filamentous fungal cell according to  claim 29  in a suitable culture medium under suitable conditions to express a CBH I variant; and   (b) obtaining said CBH I variant.