Thermal tolerant avicelase from
View Patent ↗The invention provides a thermal tolerant (thermostable) cellulase, AviIII, that is a member of the glycoside hydrolase (GH) family. AviIII was isolated and characterized from Acidothermus cellulolyticus and, like many cellulases, the disclosed polypeptide and/or its derivatives may be useful for the conversion of biomass into biofuels and chemicals.
1. A composition comprising an isolated genetically engineered polypeptide comprising a fragment of SEQ ID NO: 1, wherein said fragment has cellulase activity and, wherein said polypeptide was expressed in a heterologous host cell.
2. The composition of claim 1 , wherein the polypeptide comprises the glycosyl hydrolase family 74 (GH74_Ace) catalytic domain set forth by SEQ ID NO: 3, a linker, and a signal sequence.
3. The composition of claim 2 wherein the polypeptide further comprises the polypeptide sequence of SEQ ID NO: 4.
4. The composition of claim 2 wherein the polypeptide further comprises the polypeptide sequence of SEQ ID NO: 5.
5. An isolated genetically engineered polypeptide, said polypeptide comprising the sequence of SEQ ID NO:1, wherein said polypeptide was expressed in a heterologous cell.
6. The composition of claim 1 , wherein the composition is an industrial mixture suitable for degrading cellulose.
7. The industrial mixture of claim 6 , wherein the industrial mixture comprises a detergent.
8. A composition comprising an isolated genetically engineered polypeptide, said polypeptide comprising SEQ ID NO: 3 or a fragment thereof having cellulase activity, wherein said polypeptide was expressed in a heterologous host cell.
9. A fusion protein comprising SEQ ID NO: 3, or a fragment thereof having cellulase activity, and a heterologous peptide.
10. The fusion protein of claim 9 , further comprising the polypeptide of SEQ ID NO: 4 or SEQ ID NO: 5.
11. The fusion protein of claim 9 , wherein the heterologous peptide is a peptide tag.
12. The fusion protein of claim 11 , wherein the peptide tag is 6-His, thioredoxin, hemaglutinin, glutathione S-tranferase, or OmpA signal sequence tag.
13. The fusion protein of claim 9 , wherein the heterologous peptide is an agent that promotes polypeptide oligomerization, said agent selected from the group consisting of a leucine zipper and an Fc polypeptide.
14. The fusion protein of claim 13 , wherein the agent is a leucine zipper.
15. A cellulase-substrate complex comprising an isolated genetically engineered polypeptide bound to cellulose, said polypeptide comprising SEQ ID NO: 3 or a fragment of SEQ ID NO: 3 having cellulase activity, wherein said polypeptide was expressed in a heterologous host cell.
16. The composition of claim 8 further comprising a carrier.
17. The composition of claim 1 , wherein the fragment has, under the same conditions, at least the same level of cellulase activity and thermal tolerability as exhibited by the polypeptide of SEQ ID NO: 1.
18. A composition comprising an isolated genetically engineered polypeptide, said polypeptide comprising a catalytic domain of GH74_Ace, wherein said catalytic domain is the polypeptide of SEQ ID NO: 3 and wherein said polypeptide further comprises the polypeptide of SEQ ID NO: 4 or SEQ ID NO: 5.
19. The composition of claim 8 wherein said polypeptide comprises SEQ ID NO: 3.