[Chromosomal determinant of Streptomyces hygroscopicus with positive influence on resistance to bialaphos controlled by the bar gene]

Abstract

Streptomyces hygroscopicus ATCC21705 is an organism producing bialaphos, a promising ecologically safe antibiotic of peptide nature. An unknown determinant was cloned within the 1.4-kb SsH fragment of chromosomal DNA of S. hygroscopicus. Its presence along with the bar gene in the hybrid plasmid PVGB21 increased expression of the phenotype resistance to bialaphos in the recipient strain of S. lividans TK 64. Plasmid PVG B22 carrying the isolated SsH fragment did not provide resistance to the antibiotic. Transcription from the cloned fragment was revealed by RNA-DNA hybridization. It was shown that the cloned determinant had a positive action on bar gene transcription correlating with a significant increase in the activity of N-acetyltransferase in the mycelium of the transformant pVG B21.