Silk Proteins

Abstract

The present invention provides silk proteins, as well as nucleic acids encoding these proteins. The present invention also provides recombinant cells and/or organisms which synthesize silk proteins. Silk proteins of the invention can be used for a variety of purposes such as in the manufacture of personal care products, plastics, textiles, and biomedical products.

1 .- 46 . (canceled) 
     
     
         47 . A recombinant host cell comprising a polynucleotide which encodes a polypeptide having a coiled coil structure, wherein the polypeptide comprises an amino acid sequence which is at least 40% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27; and wherein
 a) the polynucleotide is operably linked to a heterologous promoter, and/or   b) the recombinant host cell is a bacterial, yeast or plant cell.   
     
     
         48 . The recombinant host cell of  claim 47 , wherein the polypeptide comprises an amino acid sequence which is at least 50% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27. 
     
     
         49 . The recombinant host cell of  claim 47 , wherein the polypeptide comprises an amino acid sequence which is at least 70% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27. 
     
     
         50 . The recombinant host cell of  claim 47 , wherein the polypeptide comprises an amino acid sequence which is at least 80% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27. 
     
     
         51 . The recombinant host cell of  claim 47 , wherein the polynucleotide comprises a nucleic acid sequence which is at least 40% identical to any one or more of SEQ ID NO:48, SEQ ID NO:49, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO:35, or SEQ ID NO:36. 
     
     
         52 . The recombinant host cell of  claim 47  which is a bacterial cell. 
     
     
         53 . The recombinant host cell of  claim 47 , wherein the polypeptide comprises an amino acid sequence which is at least 60% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27. 
     
     
         54 . The recombinant host cell of  claim 47 , wherein the polypeptide comprises an amino acid sequence which is at least 85% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27. 
     
     
         55 . The recombinant host cell of  claim 47 , wherein the coiled coil structure comprises at least 10 copies of the heptad sequence abcdefg, and wherein at least 25% of the amino acids at positions a and d are alanine residues. 
     
     
         56 . The recombinant host cell of  claim 55 , wherein the coiled coil structure comprises at least 10 copies of the heptad sequence abcdefg, and at least 25% of the amino acids at positions a, d and e are alanine residues. 
     
     
         57 . The recombinant host cell of  claim 47 , wherein the coiled coil structure comprises at least 18 copies of the heptad sequence abcdefg, and wherein at least 25% of the amino acids at positions a and d are alanine residues. 
     
     
         58 . The recombinant host cell of  claim 57 , wherein a coiled coil structure comprises at least 18 copies of the heptad sequence abcdefg, and at least 25% of the amino acids at positions a, d and e are alanine residues. 
     
     
         59 . A process for preparing a polypeptide comprising an amino acid sequence which is at least 40% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27, the method comprising cultivating the recombinant host cell of  claim 47 , under conditions which allow expression of the polynucleotide encoding the polypeptide, and recovering the expressed polypeptide. 
     
     
         60 . A recombinant host cell comprising a polynucleotide which encodes a polypeptide having a coiled coil structure, wherein the polypeptide comprises an amino acid sequence which is at least 40% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27, and wherein the coiled coil structure comprises at least 10 copies of the heptad sequence abcdefg, and wherein at least 25% of the amino acids at positions a and d are alanine residues; and wherein
 a) the polynucleotide is operably linked to a heterologous promoter, and/or   b) the recombinant host cell is a bacterial, yeast or plant cell.   
     
     
         61 . A recombinant host cell comprising a polynucleotide which encodes a polypeptide having a coiled coil structure, wherein the polypeptide comprises an amino acid sequence which is at least 80% identical to at least any one or more of SEQ ID NO:40, SEQ ID NO:41, SEQ ID NO:5, SEQ ID NO:6, SEQ ID NO:26, or SEQ ID NO:27; and wherein
 a) the polynucleotide is operably linked to a heterologous promoter, and/or   b) the recombinant host cell is a bacterial, yeast or plant cell.