A 1.8-Mb-reduced Streptomyces clavuligerus genome: relevance for secondary metabolism and differentiation
| Autor: | Y. Martínez-Burgo, Paloma Liras, Juan F. Martín, Antonio Rodríguez-García, Rosario Pérez-Redondo, Irene Santamarta, Rubén Álvarez-Álvarez, V. Robles-Reglero |
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| Rok vydání: | 2013 |
| Předmět: |
Spores
Bacterial Genetics Mutation Mutant Secondary Metabolism Streptomyces clavuligerus General Medicine Biology medicine.disease_cause biology.organism_classification Applied Microbiology and Biotechnology Genome Streptomyces Plasmid medicine Overproduction Secondary metabolism Gene Clavulanic Acid Genome Bacterial Plasmids Sequence Deletion Biotechnology |
| Zdroj: | Applied Microbiology and Biotechnology. 98:2183-2195 |
| ISSN: | 1432-0614 0175-7598 |
| DOI: | 10.1007/s00253-013-5382-z |
| Popis: | A large part (21 %) of the wild-type Streptomyces clavuligerus genome is located in a 1.8-Mb megaplasmid that greatly influences secondary metabolites biosynthesis even if the secondary metabolites are chromosomally encoded. The megaplasmid copy number may change depending on the nutritional and environmental conditions. The S. clavuligerus oppA2::aph mutant described by Lorenzana et al. (2004) does not form aerial mycelium, spores, and clavulanic acid, but overproduces holomycin. Transcriptomic studies, polymerase chain reactions (PCR), qPCR, and RT-qPCR analysis showed that S. clavuligerus oppA2::aph has a drastically reduced number of copies (about 25,000-fold lower than the parental strain) of plasmids pSCL1 (10.5 kb), pSCL2 (149.4 kb), and the megaplasmid pSCL4 (1.8 Mb). To clarify the role of the linear plasmids and the function of OppA2 in S. clavuligerus oppA2::aph we constructed oppA2 mutants which contained: (1) a normal copy number of the linear plasmids, (2) completely lack of the linear plasmids, and (3) a parA-parB pSCL4 mutant that resulted in lack of pSCL4. In addition, a strain with a functional oppA2 gene was constructed lacking the megaplasmid pSCL4. The results confirmed that the oppA2 gene is essential for clavulanic acid production, independently of the presence or absence of linear plasmids, but oppA2 has little relevance on differentiation. We demonstrated that the lack of sporulation of S. clavuligerus oppA2::aph is due to the absence of linear plasmids (particularly pSCL4) and the holomycin overproduction is largely due to the lack of pSCL4 and is stimulated by the oppA2 mutation. |
| Databáze: | OpenAIRE |
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