title: Recombinant strains for the enhanced production of bioengineered rapalogs.
abstract: The rapK gene required for biosynthesis of the DHCHC starter acid that initiates rapamycin biosynthesis was deleted from strain BIOT-3410, a derivative of Streptomyces rapamycinicus which had been subjected to classical strain and process development and capable of robust rapamycin production at titres up to 250mg/L. The resulting strain BIOT-4010 could no longer produce rapamycin, but when supplied exogenously with DHCHC produced rapamycin at titres equivalent to its parent strain. This strain enabled mutasynthetic access to new rapalogs that could not readily be isolated from lower titre strains when fed DHCHC analogs. Mutasynthesis of some rapalogs resulted predominantly in compounds lacking late post polyketide synthase biosynthetic modifications. To enhance the relative production of fully elaborated rapalogs, genes encoding late-acting biosynthetic pathway enzymes which failed to act efficiently on the novel compounds were expressed ectopically to give strain BIOT-4110. Strains BIOT-4010 and BIOT-4110 represent valuable tools for natural product lead optimization using biosynthetic medicinal chemistry and for the production of rapalogs for pre-clinical and early stage clinical trials.
authors.affiliation: Biotica Technology Ltd, 3 Riverside Suite 5, Granta Park, Cambridge CB21 6AD, UK.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Kendrew
authors.forename: Hrvoje
authors.initials: H
authors.lastname: Petkovic
authors.forename: Sabine
authors.initials: S
authors.lastname: Gaisser
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Ready
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Gregory
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Coates
authors.forename: Mohammad
authors.initials: M
authors.lastname: Nur-E-Alam
authors.forename: Tony
authors.initials: T
authors.lastname: Warneck
authors.forename: Dipen
authors.initials: D
authors.lastname: Suthar
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Foster
authors.forename: Leonard
authors.initials: L
authors.lastname: McDonald
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schlingman
authors.forename: Frank E
authors.initials: FE
authors.lastname: Koehn
authors.forename: Jerauld S
authors.initials: JS
authors.lastname: Skotnicki
authors.forename: Guy T
authors.initials: GT
authors.lastname: Carter
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Moss
authors.forename: Ming-Qiang
authors.initials: MQ
authors.lastname: Zhang
authors.forename: Christine J
authors.initials: CJ
authors.lastname: Martin
authors.forename: Rose M
authors.initials: RM
authors.lastname: Sheridan
authors.forename: Barrie
authors.initials: B
authors.lastname: Wilkinson
mesh_terms: D024861:Genetic Enhancement / Q000379:methods*; D016297:Mutagenesis, Site-Directed / Q000379:methods*; D011995:Recombination, Genetic / Q000235:genetics*; D020123:Sirolimus / Q000302:isolation & purification / Q000378:metabolism*; D013045:Species Specificity; D013302:Streptomyces / Q000145:classification / Q000502:physiology*
chemical_list: D020123:Sirolimus