small dna-free liposomes stimulate transfection of streptomyces protoplasts.dna of the bacteriophage phi c31 was rendered dnase resistant by entrapment in liposomes. liposome-entrapped phi c31 dna transfected streptomyces protoplasts in the presence of 50% polyethylene glycol (peg), providing a potential alternative route to conventional peg-mediated transfection of protoplasts. however, probably partially because of low entrapment of dna, this system did not result in an effective increase in transfection efficiency over the conventional transfection procedure. a more ...19827107552
glycosylation of a streptomyces coelicolor a3(2) cell envelope protein is required for infection by bacteriophage phi c31.mutants of streptomyces coelicolor a3(2) j1929 (delta pgly) were isolated that were resistant to the streptomyces temperate phage phi c31. these strains could be transfected with phi c31 dna, but could not act as infective centres after exposure to phage. thus, it was concluded that infection was blocked at the adsorption/dna injection step. the mutants fell into three classes. class i mutants were complemented by a gene, sce87.05, isolated from the cosmid library of s. coelicolor a3(2). the pro ...200111532128
a gene encoding a homologue of dolichol phosphate-beta-d-mannose synthase is required for infection of streptomyces coelicolor a3(2) by phage (phi)c31.we have shown previously that a gene encoding a homologue to the eukaryotic dolichol-phosphate-d-mannose, protein o-d-mannosyltransferase, was required for (phi)c31 infection of streptomyces coelicolor. here we show that a gene encoding the homologue to dolichol-phosphate-mannose synthase is also essential for phage sensitivity. these data confirm the role of glycosylation in the phage receptor for (phi)c31 in s. coelicolor.200212374845
Use of phage PhiC31 integrase as a tool for zebrafish genome manipulation.On the strengths of forward genetics and embryology, the zebrafish Danio rerio has become an ideal system for the study of early vertebrate development. However, additional tools will be needed to perform more sophisticated analyses and to successfully carry this model into new areas of study such as adult physiology, cancer, and aging. As improved tools make transgenesis more and more efficient, the stage has been set for precise modification of the zebrafish genome such as are done in other mo ...201121924164
multiple novel promoters from the early region in the streptomyces temperate phage phi c31 are activated during lytic development.evidence is presented that transcription of most of the early genes in the streptomyces coelicolor a3(2) phage phi c31 is from a series of unusual promoters that depend on a function expressed early in the phi c31 lytic cycle. primer extension analysis on the 5' ends of three early mrnas, from samples prepared 10 min after induction of a thermosensitive phi c31 lysogen, showed that the 5' ends all mapped close to highly similar sequences, which are proposed to be an important part of phage-speci ...19937934940
the expression of streptomyces and escherichia coli drug-resistance determinants cloned into the streptomyces phage phi c31.lysogens obtained by infecting streptomyces albus g with a phi c31-pbr322 chimaeric prophage or its delta w12 deletion derivative had increased tetracycline resistance. the ability of the delta w12 derivative to transduce tetracycline resistance was inactivated by inserting a viomycin resistance determinant (vph) into the bamhi site of the pbr322 tet gene, and restored by excising the vph gene. another deletion mutant (delta w17) of the chimaera, carrying an intact tet gene, was normally unable ...19826292047
transcriptional analysis of the repressor gene of the temperate streptomyces phage phi c31.a 397-bp fragment that contained the 5' end of the coding region of the repressor gene of the temperature streptomyces phage phi c31 was shown by in vivo promoter-probing to possess bidirectional promoter activity. in vitro runoff transcription experiments, and high resolution transcript mapping of mrna species produced in vivo using both nuclease s1 and mung bean nuclease, indicated the probable presence of two promoters for the repressor gene with two further promoters oriented in the opposite ...19892628169
plasmid cloning vectors that integrate site-specifically in streptomyces spp.cloning vectors based on the streptomyces ambofaciens plasmid psam2 and the streptomycete phage phi c31 were developed for use in streptomyces spp. these vectors replicate in escherichia coli but integrate by site-specific recombination in streptomyces spp. both psam2-based and phi c31-based vectors transformed a number of different streptomyces spp; however, the phi c31-based vectors consistently transformed at higher frequencies than psam2-based vectors. southern analysis indicated that the ph ...19911995427
induction of a phi c31 prophage inhibits rrna transcription in streptomyces coelicolor a3(2).a lysogen of streptomyces coelicolor a3(2) containing a thermoinducible mutant of the temperate phage phi c31 (phi c31 cts1) was used to obtain synchronous phage development. filter hybridization experiments indicated a marked reduction in rrna synthesis after prophage induction. s1 nuclease mapping showed that transcription from each of the four promoters of one rrna gene set (rrnd) was reduced to approximately the same extent, and that inhibition required protein synthesis. crude preparations ...19901708439
plasmid cloning vectors for the conjugal transfer of dna from escherichia coli to streptomyces spp.we have constructed cloning vectors for the conjugal transfer of dna from escherichia coli to streptomyces spp. all vectors contain the 760-bp orit fragment from the incp plasmid, rk2. transfer functions need to be supplied in trans by the e. coli donor strain. we have incorporated into these vectors selectable antibiotic-resistance markers (amr, thr, spr) that function in streptomyces spp. and other features that should allow for: (i) integration via homologous recombination between cloned dna ...19921628843
transcription map of the early region of the streptomyces bacteriophage phi c31.streptomyces coelicolor a3(2), lysogenised by the temperature-sensitive cts1 mutant of phi c31, can be synchronously induced into the lytic cycle by heat treatment. a transcription map of 10 kb of the phi c31 early gene cluster was deduced using low-resolution s1 nuclease mapping of rna prepared 10 min after induction. at least nine early transcripts, early (e)rnas 1-9, were localised reading exclusively rightwards with respect to the standard physical map of phi c31. the mrnas were extensively ...19921452040
the glucose kinase gene of streptomyces coelicolor a3(2): its nucleotide sequence, transcriptional analysis and role in glucose repression.mutants (glk) of streptomyces coelicolor a3(2) that are resistant to the non-utilizable glucose analogue 2-deoxyglucose are deficient in glucose kinase activity, defective in glucose repression, and usually unable to utilize glucose. a 2.9 kb bcli fragment, previously shown to restore a wild-type phenotype to a glk deletion mutant that lacks the entire segment, contains two complete open reading frames that would encode proteins of 20.1 kda (orf2) and 33.1 kda (orf3). orf3 is transcribed from it ...19921435260
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