Patent
The present invention provides a novel cellulase nucleic acid sequence, designated mHKcel, and the corresponding mHKcel amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding mHKcel, recombinant mHKcel proteins and methods for producing the same.
1. An isolated polynucleotide selected from the group consisting of:
(a) a nucleic acid sequence having at least 95% sequence identity to the nucleic acid sequence of SEQ ID NO:2, or the full complement thereof; and
(b) a nucleic acid sequence which encodes a polypeptide having at least 95% sequence identity to the amino acid sequence of SEQ ID NO:3;
wherein said isolated polynucleotide encodes a polypeptide having cellulase activity.
2. An isolated polynucleotide comprising
a nucleic acid sequence that hybridizes to the nucleic acid sequence of SEQ ID NO:2, under high stringency conditions, wherein said high stringency conditions are conducted at 42° C. in 50% formamide, 6×SSC, 5× Denhardt's solution, 0.5% SDS and 100 pg/ml denatured carrier DNA followed by washing two times in 2× SSPE and 0.5% SDS at room temperature and two additional times in 0.1 SSPE and 0.5% SDS at 42° C. and wherein said isolated polynucleotide encodes a polypeptide having cellulase activity.
3. The isolated polynucleotide of claim 1 wherein the polynucleotide is selected from the group consisting of mRNA, DNA, cDNA, and genomic DNA.
4. The isolated polynucleotide of claim 3 , wherein said polynucleotide is a DNA molecule.
5. A recombinant Trichoderma host cell transformed with the isolated polynucleotide of claim 1 .
6. The host cell of claim 5 , wherein said host cell is Trichoderma reesei.
7. An expression vector comprising the polynucleotide of claim 1 .
8. An expression vector comprising the isolated polynucleotide of claim 1 .
9. The expression vector of claim 8 , comprising a regulatory polynucleotide sequence with a promoter sequence from a glucose isomerase gene of Actinoplanes and a signal sequence from a Streptomyces cellulase gene.
10. A recombinant host cell transformed with the vector of claim 7 .
11. The host cell of claim 10 , which is a prokaryotic cell.
12. The host cell of claim 10 , which is a eukaryotic cell.
13. A method of producing a cellulase comprising the steps of:
(a) culturing the host cell of claim 10 in a suitable culture medium under suitable conditions wherein the isolated polynucleotide is expressed to produce the cellulase; and
(b) recovering said cellulase.
14. The method of claim 13 , wherein the host cell is a filamentous fungi or yeast cell.
15. The method of claim 13 , wherein the host cell is a bacterium.
16. The method of claim 15 , wherein the host cell is a Streptomyces.
17. The isolated polynucleotide of claim 1 , wherein the polynucleotide is SEQ ID NO:2.