Combinatorial polyketide libraries produced using a modular PKS gene cluster as scaffold
OwnerGary Ashley, Melanie C. Betlach +3inventors
InventorsGary Ashley, Melanie C. Betlach, Mary Betlach, Robert McDaniel, Li Tang
Life of this patent
Estimating the term…
Abstract
Combinatorial libraries of polyketides can be obtained by suitable manipulation of a host modular polyketide synthase gene cluster such as that which encodes the PKS for picromycin. The combinatorial library is useful as a source of pharmaceutically active compounds. In addition, novel polyketides and antibiotics are prepared using this method.
Claims39
An isolated nucleic acid which comprises a nucleotide sequence encoding at least one activity of a picromycin PKS.
An isolated nucleic acid which comprises a nucleotide sequence encoding picK, the narbomycin 12-hydroxylase gene, or which comprises a nucleotide sequence encoding the desosaminyl transferase gene from S. venezuelae.
A recombinant nucleic acid molecule which comprises a first nucleotide sequence encoding at least one activity of the picromycin PKS operably linked to at least one second nucleotide sequence that effects the expression of said first nucleotide sequence in a recombinant host.
A method to prepare a nucleic acid with the nucleotide sequence encoding a modified PKS from a nucleotide sequence encoding the picromycin PKS wherein said picromycin PKS contains first regions that encode enzymatic activities and second regions which encode scaffolding amino acid sequences, which method comprises modifying at least one said first region.
A hybrid PKS encoding nucleic acid molecule which comprises a portion of the erythromycin PKS and a portion of the picromycin PKS.
A recombinant nucleic acid molecule which comprises a first nucleotide sequence encoding picK, the narbomycin 12-hydroxylase gene, operably linked to at least one second nucleotide sequence that effects the expression of said first nucleotide sequence in a recombinant host.
A method to obtain a polyketide hydroxylated at position 12 which method comprises culturing S. venezuelae cells modified to delete the picromycin PKS and to contain a substitute PKS for production of a precursor lacking hydroxylation at position 12.
A novel polyketide of the formula:
- 3
- including the glycosylated and isolated stereoisomeric forms thereof,
- wherein R* is a straight-chain, branched or cyclic saturated or unsaturated substituted or unsubstituted hydrocarbyl of 1-15C;
- each of R1-R6 is independently H or alkyl (1-4C);
- each of X1-X5 is independently H2, HOH or ═O;
- or
- each of X1-X5 is independently H and the compound of formula 5 contains a π-bond in the ring adjacent to the position of said X at 2-3, 4-5, 6-7, 8-9 and/or 10-11;
- and
- wherein at least one of X* and X** is OH;
- and
- wherein at least two of R1-R6 are alkyl.
Dependencies are inferred from the claim text.