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Liu W,
Ahlert J,
Gao Q,
Wendt-Pienkowski E,
Shen B,
Thorson JS,
( 2003 ) Rapid PCR amplification of minimal enediyne polyketide synthase cassettes leads to a predictive familial classification model. PMID : 14528002 : DOI : 10.1073/pnas.2034291100 PMC : PMC218695 Abstract >>
A universal PCR method for the rapid amplification of minimal enediyne polyketide synthase (PKS) genes and the application of this methodology to clone remaining prototypical genes from producers of structurally determined enediynes in both family types are presented. A phylogenetic analysis of the new pool of bona fide enediyne PKS genes, consisting of three from 9-membered producers (neocarzinostatin, C1027, and maduropeptin) and three from 10-membered producers (calicheamicin, dynemicin, and esperamicin), reveals a clear genotypic distinction between the two structural families from which to form a predictive model. The results from this study support the postulation that the minimal enediyne PKS helps define the structural divergence of the enediyne core and provides the key tools for generating enediyne hybrid genes/molecular scaffolds; by using the model, a classification is also provided for the unknown enediyne PKS genes previously identified via genome scanning.
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2. |
Hamano Y,
Furumai T,
Oki T,
( 1999 ) Development of a self-cloning system for Actinomadura verrucosospora and identification of polyketide synthase genes essential for production of the angucyclic antibiotic pradimicin. PMID : 10347064 : PMC : PMC91399 Abstract >>
A self-cloning system for Actinomadura verrucosospora, a producer of the angucyclic antibiotic pradimicin A (PRM A), has been developed. The system is based on reproducible and reliable protoplasting and regeneration conditions for A. verrucosospora and a novel plasmid vector that consists of a replicon from a newly found Actinomadura plasmid and a selectable marker cloned from the Actinomadura strain. The system has an efficiency of more than 10(5) CFU/microgram of DNA. Using this system, we have cloned and identified the polyketide synthase (PKS) genes essential for PRM A biosynthesis from A. verrucosospora. Nucleotide sequence analysis of the 3.5-kb SalI-SphI fragment showed that ketosynthase subunits (open reading frame 1 [ORF1] and ORF2) of the essential PKS genes have strong similarities (59 to 89%) to those for angucyclic antibiotic biosynthesis.
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