Patent ID: 8030052
Filing Date: 2011-10-04
Classification: C12N,C12P,C12R

Abstract:
1. A midecamycin-producing mutant of a Streptomyces mycarofacines strain ATCC 21454, wherein said mutant comprises a polyketide synthetase gene cluster that encodes a polyketide synthetase that produces a polyketide involved in midecamycin biosynthesis, wherein said polyketide synthetase gene cluster comprises an open-reading frame (ORF) encoding an initiation module, and several ORFs each encoding a separate extender module, wherein one of said several ORFs is ORF1, which encodes a β-ketoacyl-acyl carrier protein synthase domain KS2, and wherein another of said several ORFs is ORF2, which encodes a β-ketoacyl-acyl carrier protein synthase domain KS3, wherein the nucleotide sequence encoding the β-ketoacyl-acyl carrier protein synthase domain KS2 in ORF1 encodes the amino acid sequence of SEQ ID NO:12, and wherein the nucleotide sequence encoding the β-ketoacyl-acyl carrier protein synthase domain KS3 in ORF2 is substituted so as to encode the amino acid sequence of SEQ ID NO:12, whereby midecamycin production is improved.