Gene cluster for streptomycin biosynthesis in Streptomyces griseus: Analysis of a central region including the major resistance gene

Abstract

A central segment of a cluster of biosynthetic genes for the antibiotic streptomycin cloned from Streptomyces griseus was analysed for open reading frames, as well as for transcriptional and translational activity. The nucleotide sequence revealed two significant open reading frames, ORF1 and APH(6), orientated in opposite directions and with a spacer of 885 bp between the start codons. The first, ORF1, had a coding capacity of 38 kDa. One open reading frame, APH(6), was identified as the major resistance gene coding for streptomycin 6-phosphotransferase, a protein of 307 amino acid residues and 33 kDa. Sequence determination of the first 14 N-terminal amino acid residues of the purified APH(6) enzyme protein was in agreement with the proposed primary structure. The possible identity of the presumed gene product of ORF1 with an in vitro translated protein (apparent molecular weight 41 kDa) is discussed. Comparison of the two APH(6) genes from S. griseus and the hydroxystreptomycin-producing S. glaucescens (cf. Vögtli and Hütter 1987) revealed 75% nucleotide sequence homology in the coding region and 74% conservation of the polypeptide sequence. Two protein domains which are highly conserved in other antibiotic and protein phosphotransferases were detected.

Biosynthetic genes for aminoglycoside antibiotics

“…A partial streptomycin biosynthetic gene cluster was then identified in 1987. 13 Subsequently, several biosynthetic genes for streptomycin were identified in association with the central gene cluster. 14 However, only a few biosynthetic genes were heterologously expressed and investigated to characterize the function to date.…”

Isolation and nucleotide sequencing of an aminocyclitol acetyltransferase gene from Streptomyces rimosus forma paromomycinus

“…Indeed, a variety of promoters sharing little or no sequence resemblance with other bacterial promoters have been found (3,10,17), which suggests that special sigma factors of the Streptomyces RNA polymerase may be involved in transcription (31). Moreover, the genes encoding antibiotic resistances in drug-producing organisms may be linked to the genes involved in antibiotic biosynthesis (9,18) and thus could be used as probes to isolate the biosynthetic pathways of secondary metabolites.…”

Molecular cloning and expression in Escherichia coli of the Bacillus licheniformis bacitracin synthetase 2 gene

“…Recent studies on the organization of the structural genes for the enzymes involved in antibiotic biosynthesis in the genus Streptomyces revealed that these genes are clustered (4). In the case of peptide antibiotics produced by bacteria of the genus Bacillus, the organization of the genes for the peptide antibiotic synthetases is not yet clarified, because until now genes for only one component enzyme of the multicomponent synthetases have been cloned.…”