Temperate Phages of Streptomyces venezuelae: Lysogeny and Host Specificity Shown by Phages SV1 and SV2

Stuttard, C.

doi:10.1099/00221287-128-1-115

Cited by 95 publications

(88 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The plasmids, phage and bacteria used are described in Table 1. Strains of S. venezuelae were maintained on MYM agar (Stuttard, 1982). Where needed for selection, either apramycin (Am, 50 mg ml 21 ) or an Am/thiostrepton (Ts) mixture (25 mg ml 21 each) was added to the growth medium.…”

Section: Methodsmentioning

confidence: 99%

Biosynthesis of the dichloroacetyl component of chloramphenicol in Streptomyces venezuelae ISP5230: genes required for halogenation

2004

View full text Add to dashboard Cite

Five ORFs were detected in a fragment from the Streptomyces venezuelae ISP5230 genomic DNA library by hybridization with a PCR product amplified from primers representing a consensus of known halogenase sequences. Sequencing and functional analyses demonstrated that ORFs 11 and 12 (but not ORFs 13-15) extended the partially characterized gene cluster for chloramphenicol (Cm) biosynthesis in the chromosome. Disruption of ORF11 (cmlK) or ORF12 (cmlS) and conjugal transfer of the insertionally inactivated genes to S. venezuelae gave mutant strains VS1111 and VS1112, each producing a similar series of Cm analogues in which unhalogenated acyl groups replaced the dichloroacetyl substituent of Cm. 1 H-NMR established that the principal metabolite in the disrupted strains was the a-N-propionyl analogue. The sequence of CmlK implicated the protein in adenylation, and involvement in halogenation was inferred from biosynthesis of analogues by the cmlK-disrupted mutant. A role in generating the dichloroacetyl substituent was supported by partial restoration of Cm biosynthesis when a cloned copy of cmlK was introduced in trans into VS1111. Complementation of the mutant also indicated that inactivation of cmlK rather than a polar effect of the disruption on cmlS expression had interfered with dichloroacetyl biosynthesis. The deduced CmlS sequence resembled sequences of FADH 2 -dependent halogenases. Conjugal transfer of cmlK or cmlS into S. venezuelae cml-2, a chlorination-deficient strain with a mutation mapped genetically to the Cm biosynthesis gene cluster, did not complement the cml-2 lesion, suggesting that one or more genes in addition to cmlK and cmlS is needed to assemble the dichloroacetyl substituent. Insertional inactivation of ORF13 did not affect Cm production, and the products of ORF14 and ORF15 matched Streptomyces coelicolor A3(2) proteins lacking plausible functions in Cm biosynthesis. Thus cmlS appears to mark the downstream end of the gene cluster.

show abstract

Section: Methodsmentioning

confidence: 99%

Biosynthesis of the dichloroacetyl component of chloramphenicol in Streptomyces venezuelae ISP5230: genes required for halogenation

2004

View full text Add to dashboard Cite

show abstract

“…For Micrococcus luteus the medium used was GNY (Malik & Vining, 1970). Streptomyces venezuelae was maintained on MYM agar (Stuttard, 1982) supplemented with antibiotics as needed to select strains with plasmids ; Streptomyces lividans JG10 was maintained on K1 agar (Aidoo, 1989), except when TOY agar (20 g each of Heinz tomato paste, Pablum and agar, and 2n5 g yeast extract in 1 litre water, pH 6n8), was required to enhance sporulation. For long-term maintenance of streptomycetes, spores in 20 % (v\v) glycerol were stored at k70 mC.…”

Section: Methodsmentioning

confidence: 99%

p-Aminobenzoic acid and chloramphenicol biosynthesis in Streptomyces venezuelae: gene sets for a key enzyme, 4-amino-4-deoxychorismate synthase The GenBank accession number for the sequence reported in this paper is AF189258.

Chang

Sun

et al. 2001

Microbiology

View full text Add to dashboard Cite

Amplification of sequences from Streptomyces venezuelae ISP5230 genomic DNA using PCR with primers based on conserved prokaryotic pabB sequences gave two main products. One matched pabAB, a locus previously identified in S. venezuelae. The second closely resembled the conserved pabB sequence consensus and hybridized with a 3 8 kb NcoI fragment of S. venezuelae ISP5230 genomic DNA. Cloning and sequence analysis of the 3 8 kb fragment detected three ORFs, and their deduced amino acid sequences were used in BLAST searches of the GenBank database. The ORF1 product was similar to PabB in other bacteria and to the PabB domain encoded by S. venezuelae pabAB. The ORF2 product resembled PabA of other bacteria. ORF3 was incomplete ; its deduced partial amino acid sequence placed it in the MocR group of GntR-type transcriptional regulators. Introducing vectors containing the 3 8 kb NcoI fragment of S. venezuelae DNA into pabA and pabB mutants of Escherichia coli, or into the Streptomyces lividans pab mutant JG10, enhanced sulfanilamide resistance in the host strains. The increased resistance was attributed to expression of the pair of discrete translationally coupled p-aminobenzoic acid biosynthesis genes (designated pabB/pabA) cloned in the 3 8 kb fragment. These represent a second set of genes encoding 4-amino-4-deoxychorismate synthase in S. venezuelae ISP5230. In contrast to the fused pabAB set previously isolated from this species, they do not participate in chloramphenicol biosynthesis, but like pabAB they can be disrupted without affecting growth on minimal medium. The gene disruption results suggest that S. venezuelae may have a third set of genes encoding PABA synthase.

show abstract

“…A disruption mutant defective in the relA gene resulting from replacement of relA by homologous recombination (double crossover) was isolated as described elsewhere (Paradkar & Jensen, 1995). The transformant harbouring pSMF387 was subcultured five times in a rich medium (MYM; Stuttard, 1982) containing only hygromycin (200 mg ml 21 ) and then transformants resistant to hygromycin but sensitive to thiostrepton (50 mg ml 21 ) were selected as putative relA gene disruption mutants (DrelA). The insertion inactivation of relA was confirmed by Southern hybridization (Sambrook & Russell, 2001) using the 717 bp SacII fragment, containing part of relA and part of hyg, labelled with the ECL direct nucleic acid labelling system (Amersham Pharmacia Biotech) as a probe.…”

Section: Methodsmentioning

confidence: 99%

Two relA/spoT homologous genes are involved in the morphological and physiological differentiation of Streptomyces clavuligerus

et al. 2004

View full text Add to dashboard Cite

This study is focused on the involvement of the unusual nucleotide (p)ppGpp during the morphological and physiological differentiation of Streptomyces clavuligerus. In particular, the functional and structural elements of two genes encoding the proteins RelA and Rsh were identified. The relA gene encodes an 843 aa protein (RelA), while the rsh gene encodes a 738 aa protein (Rsh). The relA and rsh genes were disrupted by the insertion of a hygromycin resistance gene and an apramycin resistance gene, respectively. The synthesis of ppGpp in the relA gene-disrupted mutant was completely eliminated under conditions of starvation for amino acids, whereas synthesis persisted, but was greatly reduced in the rsh gene-disrupted mutant. The relA gene-disrupted mutant had a bald appearance on agar plate cultures and retarded growth in submerged culture, while the rsh-disrupted mutant was unchanged in growth characteristics relative to the wild-type culture. The production of both clavulanic acid and cephamycin C were completely abolished in the relA-disrupted mutant. Thus, it is concluded that the relA gene rather than rsh is essential for morphological and physiological differentiation in S. clavuligerus and that RelA primarily governs the stringent response of S. clavuligerus to starvation for amino acids.

show abstract

Temperate Phages of Streptomyces venezuelae: Lysogeny and Host Specificity Shown by Phages SV1 and SV2

Cited by 95 publications

References 7 publications

Biosynthesis of the dichloroacetyl component of chloramphenicol in Streptomyces venezuelae ISP5230: genes required for halogenation

Biosynthesis of the dichloroacetyl component of chloramphenicol in Streptomyces venezuelae ISP5230: genes required for halogenation

p-Aminobenzoic acid and chloramphenicol biosynthesis in Streptomyces venezuelae: gene sets for a key enzyme, 4-amino-4-deoxychorismate synthase The GenBank accession number for the sequence reported in this paper is AF189258.

Two relA/spoT homologous genes are involved in the morphological and physiological differentiation of Streptomyces clavuligerus

Contact Info

Product

Resources

About