Use of heterologous expressed polyketide synthase and small molecule foldases to make aromatic and cyclic compounds

1. A method of producing a polyketide-derived aromatic, polyaromatic, cyclic or polycyclic compound, wherein the carbon atom chain length of the polyketide backbone of the compounds is selected from 6-31 carbon atoms, comprising the steps of:

a. providing a recombinant cell comprising:

i. a transgene encoding a heterologous type III polyketide synthase capable of forming a linear non-reduced polyketide compound, wherein the carbon atom chain length of the polyketide backbone of the formed compound is selected from 6-31 carbon atoms; and

ii. a transgene encoding a first heterologous small molecule foldase enzyme capable of catalyzing the formation of one or more region-specific intramolecular carbon-carbon or carbon-oxygen bonds in a linear non-reduced polyketide compound, wherein the carbon atom chain length of the polyketide backbone of the compound is one or more of 6-31 carbon atoms,

wherein the heterologous small molecule foldase enzyme is a bacterial or fungal enzyme, and wherein the genus from which said bacterial or fungal enzyme is derived is different from the genus from which said PKSIII enzyme is derived, and

wherein the recombinant cell is capable of a producing polyketide-derived aromatic, polyaromatic, cyclic or polycyclic compound, wherein the carbon atom chain length of the polyketide backbone of the compound is selected from among 6-31 carbon atoms; and

b. incubating and/or culturing the recombinant cell in a culture medium to support synthesis of the polyketide-derived aromatic, polyaromatic, cyclic or polycyclic compound.

2. The method according to claim 1 , wherein the heterologous type III polyketide synthase is selected from the group consisting of:

a. Triketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to 2-PS (SEQ ID NO:2) from Gerbera hybrid;

b. Tetraketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to PhID (SEQ ID NO:4) from Pseudomonas fluorescens;

c. Pentaketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of PCS (SEQ ID NO:6) from Aloe arborescens , ORAS (SEQ ID NO:8) from Neurospora crassa , and 1,3,6,8-tetrahydroxynaphthalene synthase (SEQ ID NO:10) from Streptomyces fulvissimus;

d. Hexaketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of PinPKS (SEQ ID NO:12) from Plumbago indica , DluHKS (SEQ ID NO:14) from Drosophyllum lusitanicum , and PzPKS (SEQ ID NO:16) from Plumbago zeylanica;

e. Heptaketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to ALS (SEQ ID NO:18) from Rheum palmatum or AaPKS3 (SEQ ID NO:20) from Aloe arborescens;

f. Octaktide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of OKS (SEQ ID NO:22), OKS2 (SEQ ID NO:24), OKS3 (SEQ ID NO:26) from Aloe arborescens or HpPKS2 (SEQ ID NO:28) from Hypericum perforatum;

g. Nonaketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to PCS F80A/Y82A/M207G (SEQ ID NO:29) from Aloe arborescens;

h. Decaketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to OKS N222G (SEQ ID NO:30) from Aloe arborescens ; and

i. Dodecaketide synthase polypeptide, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to OKS F66L/N222G (SEQ ID NO:31) from Aloe arborescens.

3. The method according to claim 1 , wherein the cell comprises one or more transgene encoding a second, third and fourth heterologous small molecule foldase enzyme capable of catalyzing the formation of one or more region-specific intramolecular carbon-carbon or carbon-oxygen bonds in a non-linear polyketide compound, and

wherein the second, third and fourth heterologous small molecule foldase enzymes are bacterial or fungal enzymes, and

wherein the genus from which said bacterial or fungal enzymes is derived is different from the genus from which the PKSIII enzyme is derived.

4. The method according to claim 3 , wherein one or more of said second, third or fourth heterologous heterologous small molecule foldase enzymes is selected from one or more of the groups consisting of:

a. Cyclase foldase, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of ZhuJ (SEQ ID NO:81) from Streptomyces sp. R1128, oxyN (SEQ ID NO:83) from Streptomyces rimosus , jadI (SEQ ID NO:85) from Streptomyces venezuelae , LndF (SEQ ID NO:86) from Streptomyces globisporus , pgaF (SEQ ID NO:89) from Streptomyces coelicoflavus , pnxK (SEQ ID NO:95) from Streptomyces sp., llpCIII (SEQ ID NO:101) from Streptomyces tendae , Act_CYC (SEQ ID NO:91) from Streptomyces coelicolor A3(2), sanE (SEQ ID NO:93) from Streptomyces ansochromogenes;

b. Cupin foldase, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of pnxL (SEQ ID NO:95) from Streptomyces sp. TA-0256, llpCII (SEQ ID NO:99) from Streptomyces tendae,

c. Cyclase foldase, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of ZhuJ-1 (SEQ ID NO:103) from Aspergillus nidulans , ZhuJ-2 (SEQ ID NO:105) from Aspergillus nidulans , ZhuJ-3 (SEQ ID NO:107) from Aspergillus nidulans , ZhuJ-4 (SEQ ID NO:109) from Aspergillus nidulan.

5. The method according to claim 3 , wherein one or more of said second, third and fourth heterologous small molecule foldase enzyme has cyclase or aromatase catalytic activity and a corresponding structural domain selected from the group consisting of:

a. a pfam04199 cyclase superfamily domain;

b. a pfam10604 or pfam03364 SRPBCC superfamily domain;

c. a pfam07876 Dabb superfamily domain;

d. a pfam04673 Polyketide synthesis cyclase superfamily domain;

e. a pfam00753 Lactamase_B/MBL fold metallo-hydrolase superfamily domain;

f. a pfam07883 Cupin-2 superfamily domain;

g. Dissected Product template (TIGR04532) domains from type I iterative PKS from filamentous fungi.

6. The method according to claim 1 , wherein said first heterologous small molecule foldase enzyme has cyclase or aromatase catalytic activity and a corresponding structural domain selected from the group consisting of:

a. a pfam04199 cyclase superfamily domain;

b. a pfam10604 or pfam03364 SRPBCC superfamily domain;

c. a pfam07876 Dabb superfamily domain;

d. a pfam04673 Polyketide synthesis cyclase superfamily domain;

e. a pfam00753 Lactamase_B/MBL fold metallo-hydrolase superfamily domain;

f. a pfam07883 Cupin-2 superfamily domain;

g. Dissected Product template (TIGR04532) domains from type I iterative PKS from filamentous fungi.

7. The method according to claim 1 , wherein said first heterologous heterologous small molecule foldase enzyme is selected from one or more of the groups consisting of:

a. SRPBCC Foldase, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of ZhuI (SEQ ID NO:33) from Streptomyces sp. R1128, pdmD (SEQ ID NO:35) from Actinomadura hibisca , sanI (SEQ NO:37) from Streptomyces sp., SANK 61196; pnxD (SEQ ID NO:39) from Streptomyces sp. TA-0256, llpCI (SEQ ID NO:41) from Streptomyces tendae ; ZhuI-1 (SEQ ID NO:66) from Aspergillus nidulans or ZhuI-2 (SEQ ID NO:69) from Aspergillus nidulans;

b. 2×SRPBCC foldase, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of gra-orf4 (SEQ ID NO:43) from Streptomyces violaceoruber , schP4 (SEQ ID NO:45) from Streptomyces fulvissimus DSM 40593, Erd4 (SEQ ID NO:47) from uncultured soil bacterium V167, med-ORF19 (SEQ ID NO:49) from Streptomyces sp. AM-7161, ssfY1 (SEQ ID NO:51) from Streptomyces sp. SF2575, oxyK (SEQ ID NO:53) from Streptomyces rimosus , Act_ARO-CYC (SEQ ID NO:55) from Streptomyces coelicolor A3(2);

c. Dabb foldase, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of AOC-1 (SEQ ID NO:71) from Aspergillus nidulans , AOC-2 (SEQ ID NO:73) from Aspergillus nidulans , AOC-3 (SEQ ID NO:75) from Aspergillus nidulans , AOC-4 (SEQ ID NO:77) from Aspergillus nidulans , or AOC-5 (SEQ ID NO:79) from Aspergillus nidulans ; and

d. Dissected PT domain, wherein the amino acid sequence of the polypeptide has at least 70% sequence identity to a sequence selected from the group consisting of wA-PT (SEQ ID NO:59) from Aspergillus nidulan to form C7-C12+C1-C10, BIK1-PT (SEQ ID NO:60) from Fusarium fujikuroi , PGL1 PT (SEQ ID NO:63) from Fusarium graminearum , mpdG_PT (SEQ ID NO:65) from Aspergillus nidulans or curs2-PT (GenBank AGC95321.1 position 1270 to 1613) from Aspergillus (SEQ ID NO:146).

8. The method according to claim 1 , wherein the recombinant cell or the recombinant cells in the one or more heterogeneous populations, is selected from among a bacterial cell, a filamentous fungal cell, a yeast cell and a plant cell.

9. The method according to claim 8 , wherein the yeast cell is an Ascomycete selected from the group consisting of Ashbya, Botryoascus, Debaryomyces, Hansenula , Kluveromyces, Lipomyces, Saccharomyces spp and the filamentous fungal cell is selected from the group consisting of Acremonium, Aspergillus, Fusarium, Humicola, Mucor, Myceliophthora, Neurospora, Penicillium, Thielavia, Tolypocladium , and Trichoderma.

10. The method according to claim 8 , wherein the bacterial cell is selected from the group consisting of: Bacillus, Streptomyces, Corynebacterium, Pseudomonas , lactic acid bacteria and an E. coli cell.

11. The method according to claim 8 , wherein the recombinant host cell is a Nicothiana benthamiana or Arabidopsis thaliana plant cell.

12. A method of producing a library of polyketide-derived aromatic, polyaromatic, cyclic, and polycyclic compounds, wherein the carbon atom chain length of the polyketide backbone of the compounds is selected from two or more of 6-31 carbon atoms, comprising the steps of:

a. providing one or more heterogeneous populations of recombinant cells, wherein each cell in the one or more populations comprises:

i. a transgene encoding a heterologous type III polyketide synthase capable of forming a linear non-reduced polyketide compound, wherein the carbon atom chain length of the polyketide backbone of the formed compound is selected from 6-31 carbon atoms; and

ii. a transgene encoding a first heterologous heterologous small molecule foldase enzyme capable of catalyzing the formation of one or more region-specific intramolecular carbon-carbon or carbon-oxygen bonds in a linear non-reduced polyketide compound, wherein the carbon atom chain length of the polyketide backbone of the compound is one or more of 6-31 carbon atoms,

wherein the heterologous small molecule foldase enzyme is a bacterial or fungal enzyme, and wherein the genus from which said bacterial or fungal enzyme is derived is different from the genus from which the PKSIII enzyme is derived, and

wherein the one or more populations of recombinant cells comprises cells capable of producing polyketide-derived aromatic, polyaromatic, cyclic, and/or polycyclic compounds, wherein the carbon atom chain length of the polyketide backbone of the compounds is selected from two or more of 6-31 carbon atoms; and

b. incubating and/or culturing the one or more heterogeneous populations of recombinant cells in a culture medium to support synthesis of the library of polyketide-derived aromatic, polyaromatic, cyclic, and polycyclic compounds.

13. The method of claim 12 , further comprising a step of:

c. screening the library of polyketide-derived aromatic, polyaromatic, cyclic, and polycyclic compounds, wherein each recombinant cell, or its clonal derivatives, present in the one or more heterogeneous population of recombinant cells is grown individually on a solid support, or individually in a liquid culture.

14. The method of claim 12 , further comprising the step of recovering the polyketide-derived aromatic, polyaromatic, cyclic, and polycyclic compounds produced by the one or more heterogeneous populations of recombinant cells or produced by one or more of the recombinant cell clones present in the one or more heterogeneous populations of recombinant cells.

15. A heterogeneous population of recombinant cells capable of producing a library of polyketide-derived aromatic, polyaromatic, cyclic, and/or polycyclic compounds, according to the method of claim 12 , wherein each cell in the population comprises:

a. a transgene encoding a heterologous type III PKS capable of forming a polyketide-derived aromatic, polyaromatic, cyclic, and/or polycyclic compound, wherein the carbon atom chain length of the polyketide backbone of the formed compound is selected from 6-31 carbon atoms; and

b. a transgene encoding a first heterologous heterologous small molecule foldase enzyme capable of catalyzing the formation of one or more specific intramolecular carbon-carbon bonds in a polyketide-derived aromatic, polyaromatic, cyclic and polycyclic compound, wherein the carbon atom chain length of the polyketide backbone of the compound is one or more of 6-31 carbon atoms,

wherein the heterologous small molecule foldase enzyme is a bacterial or fungal enzyme, and wherein the genus from which said bacterial or fungal enzyme is derived is different from the genus from which the PKSIII enzyme is derived,

wherein the population of recombinant cells comprises cells capable of producing polyketide-derived aromatic, polyaromatic, cyclic, and/or polycyclic compounds, wherein the carbon atom chain length of the polyketide backbone of the compounds is selected from two or more of 6-31 carbon atoms.

16. The heterogeneous population of recombinant cells of claim 15 , wherein each cell in the population further comprises one or more transgene encoding a second, third and fourth heterologous heterologous small molecule foldase enzyme capable of catalyzing the formation of one or more region-specific intramolecular carbon-carbon or carbon-oxygen bonds in a non-linear polyketide compound, and wherein the second, third and fourth heterologous small molecule foldase enzymes are bacterial or fungal enzymes, and wherein the genus from which said bacterial or fungal enzymes is derived is different from the genus from which the PKSIII enzyme is derived.