3-EPIMERASE
A protein comprising a polypeptide sequence having at least 70% sequence identity to SEQ ID NO: 6, SEQ ID NO: 2 or SEQ ID NO: 4. The protein has ketose 3-epimerase activity.
1 . A protein comprising a polypeptide sequence having at least 70% sequence identity to SEQ ID NO: 6, SEQ ID NO: 2 or SEQ ID NO: 4, wherein the protein has ketose 3-epimerase activity.
2 . A protein according to claim 1 , wherein the polypeptide sequence has at least 90% sequence identity to SEQ ID NO: 6, SEQ ID NO: 2 or SEQ ID NO: 4.
3 . A protein according to claim 1 , wherein the polypeptide sequence comprises the sequence of SEQ ID NO: 13.
4 . A protein according to claim 1 , wherein the protein is immobilized on a solid substrate.
5 . A nucleic acid molecule comprising a polynucleotide sequence encoding a protein according to claim 1 .
6 . A nucleic acid molecule according to claim 5 , comprising a polynucleotide sequence which:
i) has at least 70% sequence identity to SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3; or
ii) hybridizes under highly stringent conditions to a polynucleotide having a sequence complementary to the sequence set forth in SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3.
7 . A vector comprising a nucleic acid molecule according to claim 5 .
8 . A host cell comprising a recombinant nucleic acid molecule according to claim 5 .
9 . A host cell according to claim 8 , wherein the host cell is a yeast, bacterium or other microorganism, or is a mammalian, plant or other cell culture.
10 . A host cell according to claim 9 , wherein the host cell is E. coli.
11 . Allulose produced by a protein according to claim 1 .
12 . A method of producing allulose comprising contacting a protein according to claim 1 with a fructose substrate under conditions such that the fructose substrate is converted into allulose.
13 . A method according to claim 12 , wherein the protein is present in a host cell.
14 . A method according to claim 12 , wherein the protein is in isolated form.
15 . A method according to claim 12 , wherein the conditions comprise maintaining the protein and the fructose substrate at a temperature between 25° C. and 75° C.
16 . A method according to claim 12 , wherein the conditions comprise maintaining the protein and the fructose substrate between pH 4 and pH10.
17 . A method according to claim 12 , wherein the conditions comprise maintaining the fructose substrate concentration between 75% and 95% (WN).
18 . A nucleic acid molecule comprising a polynucleotide sequence which:
i) has at least 70% sequence identity to SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3; or
ii) hybridizes under highly stringent conditions to a polynucleotide having a sequence complementary to the sequence set forth in SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3.
19 . A host cell comprising a recombinant nucleic acid molecule comprising a polynucleotide sequence encoding a polypeptide having ketose 3-epimerase activity, wherein the polynucleotide sequence:
i) has at least 70% sequence identity to SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3; or
ii) hybridizes under highly stringent conditions to a polynucleotide having a sequence complementary to the sequence set forth in SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3.
20 . A vector comprising a nucleic acid molecule comprising a polynucleotide encoding a polypeptide having ketose 3-epimerase activity, wherein the polynucleotide sequence:
i) has at least 70% sequence identity to SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3; or
ii) hybridizes under highly stringent conditions to a polynucleotide having a sequence complementary to the sequence set forth in SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3.
21 . A method of producing allulose comprising the steps of:
i) providing a vector comprising a nucleic acid molecule having a polynucleotide sequence encoding a protein having ketose 3-epimerase activity wherein the polynucleotide sequence: a) has at least 70% sequence identity to SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3; or b) hybridizes under highly stringent conditions to a polynucleotide having a sequence complementary to the sequence set forth in SEQ ID NO: 5, SEQ ID NO: 1 or SEQ ID NO: 3;
ii) synthesising the protein having ketose 3-epimerase activity encoded by the polynucleotide sequence;
iii) contacting fructose with the protein having ketose 3-epimerase activity and maintaining the fructose and protein under conditions to permit the conversion of fructose to allulose; and
iv) at least partially purifying the allulose produced in step iii).