Isoprenoid compounds
First Claim
1. A nucleic acid molecule that encodes a variant squalene synthase enzyme, wherein the variant enzyme comprises one or more amino acid substitutions in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO:
- 4, and comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
4, whereby;
the variant enzyme exhibits reduced cellular squalene synthase activity compared to the enzyme that does not comprise the one or more amino acid substitution(s);
the variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and
the eukaryotic microbial host produces a terpene product in medium lacking a sterol.
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Accused Products
Abstract
The present invention is directed to variant squalene synthase enzymes, including Saccharomyces cerevisiae squalene synthase enzymes, and to nucleic acid molecules encoding these variant enzymes. These variant enzymes produce squalene at a lower rate than the wild-type enzyme, allowing more farnesyl pyrophosphate to be utilized for production of isoprenoid compounds, while still producing sufficient squalene to allow the S. cerevisiae cells to grow without the requirement for supplementation by sterols such as ergosterol. These variant enzymes, therefore, are highly suitable for the efficient production of isoprenoids.
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Citations
49 Claims
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1. A nucleic acid molecule that encodes a variant squalene synthase enzyme, wherein the variant enzyme comprises one or more amino acid substitutions in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO:
- 4, and comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
4, whereby;the variant enzyme exhibits reduced cellular squalene synthase activity compared to the enzyme that does not comprise the one or more amino acid substitution(s); the variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and the eukaryotic microbial host produces a terpene product in medium lacking a sterol. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
- 4, and comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
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12. An isolated nucleic acid molecule that encodes a variant squalene synthase enzyme, wherein:
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the variant enzyme comprises amino acid substitution(s) selected from among E149G/G168V/Y181N/Q290L/I323T, V186I, Y330H, Y181N/L271I/S275G/N320D, M214T/I242V/V277A/Q290L, E13V/L60P, D125V, L130P, V56L/S335P and H89Y/F110L/R224G/K251G in a wild-type Saccharomyces squalene synthase enzyme; the variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, exhibits reduced activity compared to the wild-type squalene synthase enzyme, and catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth. - View Dependent Claims (13, 14)
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15. An isolated nucleic acid molecule that encodes a modified squalene synthase enzyme, wherein:
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the encoded variant squalene synthase enzyme has at least 95% sequence identity with the squalene synthase whose sequence is set forth in SEQ ID NO;
4; andthe isolated nucleic acid molecule comprises the nucleic acid modifications selected from among A691G/G748T/T786A/A1114T/T1213C/T1290C, C72A/110Δ
A/G801A, T989A/G1112A/G1220A/T1233C, T786A/A1025G/T1056A/A1068G/A1203G, T886C/A969G/T1075C/A1114T, T84A/A283T/T424C/A440G/T1076C, A619T/T634C/C962T, A150T/T410G/G411T/T1248C and C510T/T573C/A918G/A997G. - View Dependent Claims (16, 17, 18, 19)
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34. A variant squalene synthase enzyme, comprising one or more amino acid substitutions in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO:
- 4, and the variant enzyme comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
4, whereby;the variant enzyme exhibits reduced cellular squalene synthase activity compared to wild-type enzyme, but when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and the host produces a terpene product in medium lacking a sterol. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43)
- 4, and the variant enzyme comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
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44. A variant squalene synthase enzyme, comprising substitutions selected from among E149G/G168V/Y181N/Q290L/I323T, V186I, Y330H, Y181N/L271I/S275G/N320D, M214T/I242V/V277A/Q290L, E13V/L60P, D125V, L130P, V56L/S335P and H89Y/F110L/R224G/K251G, wherein:
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the unmodified squalene synthase comprises the sequence of amino acids set forth in SEQ ID NO;
4 or a sequence of amino acids having at least 95% sequence identity therewith; andthe variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, exhibits reduced activity compared to the enzyme without the amino acid substitutions, and catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth. - View Dependent Claims (45)
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46. A nucleic acid molecule that encodes a variant squalene synthase enzyme, wherein the variant enzyme comprises an amino acid substitution in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO:
- 4 or in a squalene synthase enzyme having at least 95% sequence identity therewith, whereby;
the variant enzyme exhibits reduced cellular squalene synthase activity compared to the enzyme that does not comprise the amino acid substitution; the variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and the eukaryotic microbial host produces farnesyl pyrophosphate or premnaspirodiene in medium lacking a sterol.
- 4 or in a squalene synthase enzyme having at least 95% sequence identity therewith, whereby;
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47. An isolated nucleic acid molecule encoding a Saccharomyces cerevisiae squalene synthase that comprises the nucleic acid modifications selected from among A691G/G748T/T786A/A1114T/T1213C/T1290C, C72A/110Δ
- A/G801A, T989A/G1112A/G1220A/T1233C, T786A/A1025G/T1056A/A1068G/A1203G, T886C/A969G/T1075C/A1114T, T84A/A283T/T424C/A440G/T1076C, A619T/T634C/C962T, A150T/T410G/G411T/T1248C and C510T/T573C/A918G/A997G, wherein the unmodified Saccharomyces cerevisiae squalene synthase comprises the sequence of amino acids set forth in SEQ ID NO;
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- A/G801A, T989A/G1112A/G1220A/T1233C, T786A/A1025G/T1056A/A1068G/A1203G, T886C/A969G/T1075C/A1114T, T84A/A283T/T424C/A440G/T1076C, A619T/T634C/C962T, A150T/T410G/G411T/T1248C and C510T/T573C/A918G/A997G, wherein the unmodified Saccharomyces cerevisiae squalene synthase comprises the sequence of amino acids set forth in SEQ ID NO;
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48. A nucleic acid molecule that encodes a variant squalene synthase enzyme, wherein the variant enzyme comprises an amino acid substitution in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO:
- 4 or in a squalene synthase enzyme having at least 95% sequence identity therewith, whereby;
the variant enzyme exhibits reduced cellular squalene synthase activity compared to the enzyme that does not comprise the amino acid substitution; the variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and the eukaryotic microbial host produces a terpene product in medium lacking a sterol such that the level of the terpene product is at least equivalent to the level of terpene product produced by the strain of the eukaryotic microbial host that requires a sterol in the medium for growth.
- 4 or in a squalene synthase enzyme having at least 95% sequence identity therewith, whereby;
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49. A variant squalene synthase enzyme, comprising an amino acid substitution in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO:
- 4 or in a squalene synthase enzyme having at least 95% sequence identity therewith, wherein the variant enzyme comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
4, whereby;the variant enzyme exhibits reduced cellular squalene synthase activity compared to the enzyme that does not comprise the amino acid substitution, but when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and the eukaryotic microbial host produces a terpene product in medium lacking a sterol such that the level of the terpene product is at least equivalent to the level of terpene product produced by the strain of the eukaryotic microbial host that requires a sterol in the medium for growth.
- 4 or in a squalene synthase enzyme having at least 95% sequence identity therewith, wherein the variant enzyme comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO;
Specification