Cloning and Analysis of a DNA Fragment Stimulating Avermectin Production in Various Streptomyces avermitilis Strains
AUTOR(ES)
Hwang, Yong-Soon
FONTE
American Society for Microbiology
RESUMO
To isolate a gene for stimulating avermectin production, a genomic library of Streptomyces avermitilis ATCC 31267 was constructed in Streptomyces lividans TK21 as the host strain. An 8.0-kb DNA fragment that significantly stimulated actinorhodin and undecylprodigiosin production was isolated. When wild-type S. avermitilis was transformed with the cloned fragment, avermectin production increased approximately 3.5-fold. The introduction of this fragment into high-producer (ATCC 31780) and semi-industrial (L-9) strains also resulted in an increase of avermectin production by more than 2.0- and 1.4-fold, respectively. Subclones were studied to locate the minimal region involved in stimulation of pigmented-antibiotic and avermectin production. An analysis of the nucleotide sequence of the entire DNA fragment identified eight complete and one incomplete open reading frame. All but one of the deduced proteins exhibited strong homology (68 to 84% identity) to the hypothetical proteins of Streptomyces coelicolor A3(2). The orfX gene product showed no significant similarity to any other protein in the databases, and an analysis of its sequence suggested that it was a putative membrane protein. Although the nature of the stimulatory effect is still unclear, the disruption of orfX revealed that this gene was intrinsically involved in the stimulation of avermectin production in S. avermitilis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=143579Documentos Relacionados
- Cloning and Analysis of a DNA Fragment Stimulating Avermectin Production in Various Streptomyces avermitilis Strains
- Involvement of glucose catabolism in avermectin production by Streptomyces avermitilis.
- Genetic studies of avermectin biosynthesis in Streptomyces avermitilis.
- Deletion analysis of the avermectin biosynthetic genes of Streptomyces avermitilis by gene cluster displacement.
- Transposon mutagenesis by Tn4560 and applications with avermectin-producing Streptomyces avermitilis.