This article describes mutants of the native and industrial high producing strain of Saccharapolyspora erythraea with inactivated and overexpressed regulatory gene SACE_5599, which have been generated based on the results obtained in WP3 and better understanding of homologous recombination. Inactivation of SACE_5599 in the highproducing strain significantly reduced erythromycin yield, in addition to drastically decreasing sporulation intensity. In contrast, overexpression of SACE_5599 in the wild type NRRL23338 strain resulted in an increase of erythromycin yield by 32%. After identifying the regulatory gene bldD, SACE_5599 is the second putative regulatory gene to be identified in S. erythraea, which has a positive influence on erythromycin yield. Similarly to bldD, SACE_5599 is involved in morphological development of S. erythraea, suggesting a very close relationship between secondary metabolite biosynthesis and morphological differentiation in this organism.
COBISS.SI-ID: 3005775
This article describes the annotation of gene clusters for biosynthesis of natural products, containing modular biosynthetic enzymes polyketide synthases (PKS) and nonribosomal peptide synthetases (NRPS) in the genome of S. tsukubaensis, recently sequenced by Acies Bio. The analysis of these very large genes in genomes obtained by pyrosequencing is demanding as gene clusters are distributed among several contigs, sequencing errors can introduce apparent frame-shifts and in addition, these genes often contain very long repetitive regions. The article describes the analysis of the genome by phylogenetic approach and the ClustScan program, which enabled the identification of 4 PKS gene clusters and 6 NRPS gene clusters in the genome of S. tsukubaensis. In addition, PCR and sequencing enabled us to correct apparent frame-shifts and RT-PCR approach was used to demonstrate active transcription of one of the identified gene clusters.
COBISS.SI-ID: 4142456
Streptomyces rapamycinicus strain NRRL 5491 produces the important drug rapamycin. It has a large genome of 12.7 Mb, of which over 3 Mb consists of 48 secondary metabolite biosynthesis clusters. The major scaffold was scanned for potential protein coding regions and 10,425 protein coding genes were predicted. The ClustScan program found 25 modular secondary metabolite clusters: 13 type I modular polyketide synthases (PKS), 5 nonribosomal peptide synthetases (NRPS), and 7 mixed PKSNRPS clusters, including the rapamycin biosynthesis cluster. The antiSmash program also found these modular clusters as well as 23 further secondary metabolite clusters of other types. Obtained genome sequence enables significantly improvement of understanding of recombination mechanisms in strain Streptomyces rapamycinicus and related gene homologues and thus facilitates the implementation of the project.
COBISS.SI-ID: 4278904