Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| isolation and characterization of conditional-lethal rho mutants of escherichia coli. | temperature-sensitive nita (rho) mutants of e. coli were isolated; one of them was characterized as an amber mutant. these strains show the nit phenotype (transcription of phage lambda dna independent of the n gene) at low temperatures and are inviable at high temperatures. the mutated sites appear to be between cya and mete on the chromosome. temperature-sensitive nita bacteria not only permit leftward transcription of the lambda genome at a high rate in the absence of the lambda n protein, but ... | 1977 | 322147 |
| isolation and characterization of plaque-forming lambdadnaz+ transducing bacteriophages. | the escherichia coli dnaz gene, a deoxyribonucleic acid (dna) polymerization gene, is located 1.2 min counterclockwise from pure, at approximately min 10.5 on the e. coli map. from a lysogen with lamdaci857 integrated at a secondary attachment site near pure, transducing phages (lambdadnas+) that transduced a dnazts (lambda+) recipient to temperature insensitivity (ts+) were discovered. three different plaque-forming transducing phages were isolated from seven primary heterogenotes. genetic test ... | 1977 | 323235 |
| transcription in vitro of bacteriophage lambda 4s rna: studies on termination and rho protein. | when bacteriophage lambdapga18 dna is transcribed in a purified in vitro system by e. coli rna polymerase (nucleoside triphosphate: rna nucleotidyl-transferase, ec 2.7.7.6), several major transcripts are synthesized. we have investigated transcriptional termination of one of these transcripts, the 4s, or "oop" rna. analysis by two-dimensional "fingerprinting" of t1 oligonucleotides reveals that transcription of the 4s rna terminates at a specific site on the lambdapga18 dna template, t-l with an ... | 1977 | 325526 |
| genetic characterization of plasmid formation by n- mutants of bacteriophage lambda. | 1977 | 325881 | |
| analysis of the phase variation in lambda reduced immunity lysogens. | two distinct phases characterized by different levels of immunity that appear in some e. coli strains lysogenic for reduced immunity mutants of bacteriophage lambda are identified as single and tandem double lysogens respectively on the basis of dna-dna hybridization experiments and the requirement of the phage xis function for the transition from a single to a double, and of the host reca function for the transition from a double to a single lysogen (in a xis- condition). rim lysogens with a fu ... | 1977 | 327265 |
| a specialized transducing lambda phage carrying the escherichia coli genes for phenylalanyl-trna synthetase. | a lambda phage has been isolated which specifically transduces the escherichia coli phes and phet genes coding for the alpha and beta subunits of the phenylalanyl-trna synthetase (prs). this phage transduces with high frequency (i) several temperature-sensitive prs mutants to thermoresistance and (ii) a p-fluorophenylalanine resistant prs mutant to sensitivity against this amino-acid analog. the in vitro prs activities of such lysogens suggest that the alpha and beta subunits coded by the transd ... | 1977 | 327276 |
| [the action of selected herbicides on bacteriophages and escherichia coli (author's transl)]. | the effect of eight herbicides on the multiplication of bacteria and bacteriophages was tested with escherichia coli, strains w1665f+ and c600, and with the rna-phage m12 and the dna-phage lambda in turbidimetric investigations and one-step growth experiments. e. coli is inhibited by seven of the herbicides investigated in concentrations of 10(-3)m, partly of 10(-4)m, too, and is promoted by some compounds in weaker concentrations. naphthylacetic acid, (nes) largely independent of its concentrat ... | 1977 | 327728 |
| the mechanism of action of nitro-heterocyclic antimicrobial drugs. primary target of 1-methyl-2-nitro-5-vinylimidazole is dna. | the antimicrobial drug 1-methyl-2-nitro-5-vinylimidazole (mev) preferentially blocked dna synthesis, was mutagenic and induced coliphage lambda in escherichia coli. the antibacterial effects of mev are the consequences of repairable damage to dna, as shown by hypersensitivity of reca and uvr strains to mev and related drugs, stimulation by mev of dna turnover which was dependent on the product of the uvra gene, and the presence of cross-links in dna from mev-treated bacteria. | 1977 | 330809 |
| kinetics of induction of error-prone repair of bacteriophage lambda by temperature shift in an escherichia coli dnab mutant. | preincubation at 42 degrees, before infection at permissive temperature by phage lambda, of an escherichia coli dnab mutant, provokes a significant increase in survival and mutagenesis of ultraviolet irradiated phage as well as mutagenesis of untreated phage. similarly to uv irradiation and many chemical mutagens, the inhibition of dna synthesis by temperature shift of this dnab mutant induces sos repair. this work shows that replication blockage in bacterial dna is not only mutagenic for bacter ... | 1977 | 337133 |
| in vitro packaging of a lambda dam vector containing ecori dna fragments of escherichia coli and phage p1. | in this report we describe a coliphage lambda vector system for cloning endo r. ecori dna fragments. this system differs significantly from those previously described in two ways. first, restricted and ligated dna is encapsidated in vitro. second, with increasing lambda dna size in the range 78 to 100% that of wild-type, the efficiency of dna encapsidation into infectious phage particles markedly increases. for lambda wild-type dna the efficiency of in vitro packaging (10(6) to 10(7) plaques pro ... | 1977 | 338419 |
| in vitro synthesis of beta-galactosidase with ilv-lac fusion deoxyribonucleic acid as template. | an in vitro protein-synthesizing system has been developed to study the mechanism of induction of ilvc gene in escherichia coli strain k-12. deoxyribonucleic acid (dna) from a lambda phage carrying an ilvc-lac fusion was employed as a template for the in vitro synthesis of beta-galactosidase under the control of the ilvc promoter. the use of this template allowed an investigation of the components required for induction of the ilvc gene and the kinetics of the induction. the in vitro synthesis o ... | 1977 | 411784 |
| coupling of lac mrna transcription to translation in escherichia coli cell extracts. | in an extract containing all the components for lac gene expression except washed ribosomes, lac mrna formation was increased 4- to 6-fold by the addition of washed ribosomes. the formation of beta-galactosidase mrna and enzyme showed very different dependency on added ribosomes. enzyme was formed in proportion to the number of ribosomes added, whereas 10% of the standard level of ribosomes promoted full levels of transcription. consistent with their action in vivo, chloramphenicol and erythromy ... | 1978 | 415305 |
| maximizing gene expression on a plasmid using recombination in vitro. | recombination in vitro has been used to place one or more copies of a strong promoter, the lac promoter, at varying distances from the cl (repressor) gene of bacteriophage lambda on the e. coli plasmid pmb9. in all constructions, lambda repressor synthesis is driven wholly or predominantly by the inserted lac promoter. one of our fusions directs the synthesis of very high levels of lambda repressor. in this case, the fused dna encodes a ribosome binding site which is a "hybrid" of lambda and lac ... | 1978 | 340049 |
| regulation of glutamine synthetase formation in escherichia coli: characterization of mutants lacking the uridylyltransferase. | a lambda phage (lambdank55) carrying the translocatable element tn10, conferring tetracycline resistance (tetr), has been utilized to isolate glutamine auxotrophs of escherichia coli k-12. such strains lack uridylyltransferase as a result of an insertion of the tn10 element in the glnd gene. the glnd::tn10 insertion has been mapped at min 4 on the e. coli chromosome and 98% contransducible by phage p1 with dapd. a lambda transducing phage carrying the glnd gene has been identified. a glnd::tn10 ... | 1978 | 26660 |
| the organization of ribosomal rna genes in the mitochondrial dna of tetrahymena pyriformis strain st. | 1. we have constructed a physical map of the mtdna of tetrahymena pyriformis strain st using the restriction endonucleases ecori, psti, saci, hindiii and hhai. 2. hybridization of mitochondrial 21 s and 14 s ribosomal rna to restriction fragments of strain st mtdna shows that this dna contains two 21-s and only one 14-s ribosomal rna genes. by s1 nuclease treatment of briefly renatured single-stranded dna the terminal duplication-inversion previously detected in this dna (arnberg et al. (1975) b ... | 1978 | 102353 |
| organization of the ribosomal ribonucleic acid gene cluster of neurospora crassa by means of restriction endonucleases and cloning in bacteriophage lambda [proceedings]. | 1978 | 154424 | |
| [cloning of the hepatitis b virus genome in escherichia coli]. | the whole genome of the hepatitis b virus (dane particles) was inserted in vitro in the genome of the bacteriophage lambda gtwes . lambda b. the recombinant dna molecule was cloned in e. coli. amplification of the hybrid bacteriophage enables the preparation of large amounts of hepatitis b virus dna. the possibilities offered by the utilization of this recombinant bacteriophage are discussed. | 1978 | 158442 |
| restoration of polarity by n-deficiency in lambda phage containing a translocated trp operon segment. | when translation of trp mrna is terminated by a nonsense codon or by antibiotics like chloramphenicol, the amount of the mrna distal to the blocked ribosomes is found at much lower levels ("polarity"). polarity is alleviated when the trp mrna is formed as part of a long transcript from the phage lambda promoter pl (segawa and imamoto, 1974; franklin, 1974); but the relief of polarity is itself largely dependent on the lambda protein n. in a phage that joins the trp operon segment (trpd, c, b a) ... | 1978 | 345080 |
| genes for the hook-basal body proteins of the flagellar apparatus in escherichia coli. | of the more than 30 genes required for flagellar function, 6 are located between pyrc and ptsg on the escherichia coli genetic man. this cluster of genes is called flagellar region i. four-point transductional crosses were used to establish the position and order of the region i flagellar genes with respect to the outside markers ptsg and pyrc. bacteriophage lambda-e. coli hybrids that contained most of the genes necessary for flagellar formation were constructed. the properties of specific hybr ... | 1978 | 350831 |
| transfection of escherichia coli spheroplasts: infectious lambda prophage dna. | high mol. wt. dna was extracted from escherichia coli lambda lysogens and was shown to be infectious. its infectivity was due to prophage dna integrated into the host chromosome rather than to dna released from mature phage particles, as established by the following criteria: the titre of infectious dna exceeded by 100-fold the titre of infectious units present before dna extraction; mild shear selectively reduced prophage dna infectivity to 2% of the unsheared dna while lambda phage dna infecti ... | 1978 | 351139 |
| correlation between uv dose requirement for lambda bacteriophage induction and lambda repressor concentration. | escherichia coli k-12 wild type and a uvra mutant derivative were used to construct isogenic strains bearing one, two, three, or more phage lambda ci genomes and containing increasing concentration of lambda repressor as measured by in vitro operator dna-binding assays. the survival and phage induction in response to uv irradiation were determined. in both strains, dose-response relationships were obtained as a function of the cellular repressor concentration. the uvra lysogens required one-tent ... | 1978 | 353300 |
| [molecular cloning of the structural genes of the escherichia coli deo-operon in plasmid rsf2124]. | a specialized phage lambda ddeo carrying the deo operon of escherichia coli is analyzed by exposing the dna to the specific restriction endonucleases ecori and bamhi. using the lambda ddeo dna fragment, obtained by digestion with bamhi and plasmid rsf2124 as a vehicle, the hybrid plasmid pam1 carrying all the genes of the deo operon is constructed and cloned in e. coli cells. it is shown that the activity of thymidine phosphorylase in the strain am061, which contains hybrid plasmid pam1 is 30-fo ... | 1978 | 363516 |
| bacteriophage lambda carrying the escherichia coli chromosomal region of the replication origin. | a transducing phage lambdaasn was isolated. the late gene region of its genome was found to have been substituted by an escherichia coli chromosomal segment containing the genes bgir, bgic, glms, unca, and asn. restriction endonuclease cleavage mapping and electron microscopic analysis of the lambdaasn dna revealed that the size of the bacterial segment is approximately 1.75 x 10(7) daltons, corresponding to about 26.4 kilobases. the circular dna of lambdaasn was digested with restriction endonu ... | 1978 | 368808 |
| initiation of lambda dna replication in vitro promoted by isolated p-gene product. | the product of the p gene of bacteriophage lambda was isolated from heat-induced lambda-lysogenic escherichia coli cells. it was found to bind to dna, to be devoid of nuclease activity acting on double-stranded lambda dna and of nicking/closing activity. initiation of lambda dna replication promoted by the p-gene product in a complementation assay in vitro was sensitive to rifampicin. sedimentation analysis of the products and their hybridization to separated lambda dna strands indicate that lam ... | 1978 | 342246 |
| identification of the n gene protein of bacteriophage lambda. | the n gene protein, pn, of bacteriophage lambda stimulates early gene transcription by allowing mrna chain elongation to proceed into genes distal to transcription termination sites normally recognized by the escherichia coli transcription termination protein rho. pn has previously eluded detection on sodium dodecyl sulfate/polyacrylamide gels because of its small size, its instability, and the difficulty of distinguishing pn itself both from host proteins and from other early lambda proteins wh ... | 1978 | 276863 |
| enzymatic breakage of the cohesive end site of phage lambda dna: terminase (ter) reaction. | an in vitro system is described for measuring the endonucleolytic conversion of the phage lambda cohesive end sites in concatemeric dna to the cohesive chromosomal ends of the mature molecule. this enzymic process, known as the ter reaction, is catalyzed by purified lambda a gene protein. the reaction is markedly stimulated by atp, mg2+, spermidine, and one or more uncharacterized factors present in extracts of uninfected escherichia coli cells. in vitro, the ter reaction proceeds in the absence ... | 1978 | 279909 |
| a single base-pair change creates a chi recombinational hotspot in bacteriophage lambda. | x4+ mutations, responsible for the chi phenotype in phage lambda, locally increase the rate of recombination promoted by the escherichia coli recombination system (rec). x+ mutations in the cii gene, one of a few sites in lambda at which such mutations arise, were located genetically and physically with overlapping deletions. dna sequence analysis of the deletion segment containing the x+ c mutations showed that two independent x+ c mutations arose by the same a-t to t-a transversion. presumably ... | 1978 | 282634 |
| molecular cloning of polyoma virus dna in escherichia coli: oncogenicity testing in hamsters. | inoculation of suckling hamsters with 2 x 10(8) live cells of escherichia coli k12 strain chi1776, carrying the complete genome of polyoma virus in a recombinant plasmid, failed to induce tumors in any of 32 recipients. also, lambda phage dna and particles with a monomeric insert of polyoma dna did not induce tumors. purified recombinant plasmid dna, as well as phage particles and dna containing a head-to-tail dimer of polyoma dna, showed a low degree of oncogenicity, comparable to that of polyo ... | 1979 | 224458 |
| [integration of lambda phage (author's transl)]. | 1979 | 233426 | |
| cole1 plasmid incompatibility: localization and analysis of mutations affecting incompatibility. | deletion mutants of plasmid cole1 that involve the replication origin and adjacent regions of the plasmid have been studied to determine the mechanism by which those mutations affect the expression of plasmid incompatibility. it was observed that (i) a region of cole1 that is involved in the expression of plasmid incompatibility lies between base pairs -185 and -684; (ii) the integrity of at least part of the region of cole1 dna between base pairs -185 and -572 is essential for the expression of ... | 1979 | 378980 |
| inactivation of bacteriophage lambda by combined x-ray and u.v.-light exposure. | extracellular phage lambda has been successively exposed to x-rays and u.v. light. the plaque-forming ability of the irradiated phages was determined on host cells with different repair capacities. no change in sensitivity was found with a pre-treatment of one type of radiation to lethal damage inflicted by the other. this indicates that a prerequisite for an interaction of different types of radiation is either an active metabolism or repair process occurring during the two radiation exposures. | 1979 | 381227 |
| transduction of bacteriophage lambda by bacteriophage t1. | when bacteriophage t1 was grown on bacteriophage lambda-lysogenic cells, phenotypically mixed particles were formed which had the serum sensitivity, host range, and density of t1 but which gave rise to lambda phage. t1 packaged lambda genomes more efficiently both when the length of the prophage was less than that of wild-type lambda and when the host cell was polylysogenic. expression of the red genes of lambda or the rece system of escherichia coli during t1 growth enhanced pickup of lambda by ... | 1979 | 381686 |
| in vitro transcription by wheat germ ribonucleic acid polymerase ii: effects of heparin and role of template integrity. | double-stranded deoxyribonucleic acid (dna) from bacteriophage lambda is a good template for wheat germ dna-dependent ribonucleic acid (rna) polymerase ii. we delineated conditions for obtaining maximum polymerase activity using as template both the relatively intact dna extracted from the the lambda phage and dna into which single-strand nicks have been introduced by deoxyribonuclease (dnase) i digestion. the deliberate introduction of nicks produces a modest increase in transcription. the nacl ... | 1979 | 387073 |
| interaction of bacteriophage k10 with its receptor, the lamb protein of escherichia coli. | the lamb protein of escherichia coli was initially recognized as the receptor for bacteriophage lambda. it is now shown also to constitute the receptor for phage k10. the lamb protein interacts with phage k10 in vitro, but this interaction does not lead to phage inactivation. most lambda-resistant labb mutants are also resistant to k10, and vice versa. however, a significant proportion of the mutants resistant to one of the phages is sensitive to the other. nineteen k10-resistant lambda-sensitiv ... | 1979 | 387746 |
| physical characterisation of the "rac prophage" in e. coli k12. | we confirm the hypothesis of low (1973) that many e. coli k12 strains contain a prophage (the rac prophage) located a few minutes clockwise of the trp operon on the genetic map. we have used restriction endonucleases and 32p-labelled probes to construct a physical map of this prophage. some e. coli k12 strains, including ab1157, have lost the entire prophage, apparently by a specific deletion. this is consistent with prophage excision by site-specific recombination. lambda reverse (lambda rev) p ... | 1979 | 390313 |
| construction and characterization of a plasmid coding for a fragment of the escherichia coli reca protein. | the e. coli reca gene was cloned from the phage lambda preca into the vector pbr313. a plasmid, pjl3, was also isolated by cloning a portion of the reca gene into the vector pbr322. pjl3 coded for a fragment of the reca protein 34 kd (kilodaltons) in size (compared to 40 kd for the intact protein). this fragment was antigenically related to the reca protein and its synthesis was subject to the same controls as that of the reca protein. the fragment did not express any detectable reca function. w ... | 1979 | 395410 |
| [repair of recombinant plasmids]. | comparative analysis of uv-sensitivity was carried out on plasmids of various molecular weight. recombinant plasmids containing fragments of prokaryotic dna (e. coli, phage lambda) are repaired in e. coli cells more effectively than those containing eukaryotic dna fragments. it was also shown that uv-sensitivity of recombinant plasmids is independent of their molecular weight provided that the active repair process in fact occurs. uv-sensitivity was strongly proporational to dna size only when e ... | 1979 | 398000 |
| site-specific recombination of bacteriophage lambda: the role of host gene products. | 1979 | 158465 | |
| nucleotide sequence of a secondary attachment site for bacteriophage lambda on the escherichia coli chromosome. | the nucleotide sequence of a secondary attachment site for bacteriophage lambda was determined in a region near the rrnb gene at 88 min on the e. coli chromosome. the sequence has a 8 base pair interrupted homology gct tttta to the common core of the primary attachment site (attb) and the corresponding phage sequence (attp). the site of crossover during integration lies probably between nucleotides -3 and +1. the flanking regions have no obvious homology to the arms of either attp or attb. | 1979 | 160033 |
| a rightward promoter to the left of the att site of lambda phage dna: possible participant in site-specific recombination. | the binding has been studied of escherichia coli rna-polymerase to the fragments of lambda dna obtained by digestion with restriction endonucleases bsui, hindiii, bamhi, ecori and hindii + iii. there are at least six sites of rna-polymerase binding in the b2-region. in vitro transcription of those bsui-fragments of the b2-region which contain six binding sites is rightward. therefore, the fragments contain promoters rather than mere rna-polymerase binding sites. one of the promoters of the b2 re ... | 1979 | 160359 |
| the fate of phage lambda dna in lambda-infected minicells. | the fate of phage lambda dna in lambda-infected escherichia coli minicells harboring the plasmid cole1, and in plasmid-free minicells, were studied. binding of lambda dna to the minicell membrane, and formation of the supercoiled covalently-closed circular structure has been demonstrated. phage infection abolishes plasmid dna synthesis. only a very slight, non-replicative lambda dna synthesis occurs, soon after infection. this synthesis is associated with fragments of lambda dna arising during, ... | 1979 | 161175 |
| recombination of bacteriophage phi x174 by the red function of bacteriophage lambda. | recombination of bacteriophage phi x174 was effectively promoted when the red function of lambda was supplied by either co-infection with lambda or induction of lambda lysogens. mutations in red alpha and red beta genes of lambda abolished recombination nearly completely, whereas a mutation in gam gene reduced it only slightly. the red-promoted recombination of phi x174 occurred in reca, recb, and pola mutants as well as in wild-type strains of escherichia coli. it was further stimulated when ph ... | 1979 | 430603 |
| l factor that is required for beta-galactosidase synthesis is the nusa gene product involved in transcription termination. | the dna-dependent in vitro synthesis of escherichia coli beta-galactosidase requires the presence of a soluble protein referred to as l factor [kung, h., spears, c. & weissbach, h. (1975) j. biol. chem. 250, 1556-1562]. in the present study, comparison of physical, immunological, and biological properties shows that l factor is the product of the e. coli nusa gene. the nusa gene product is known to interact with bacteriophage lambda n gene protein and to prevent premature termination of transcr ... | 1980 | 6154941 |
| studies on the e. coli gronb (nusb) gene which affects bacteriophage lambda n gene function. | escherichia coli mutants, called gronb, which block the growth of bacteriophage lambda at the level of action of the gene n product, have been isolated as survivors at 42 degrees c of bacteria carrying a) the defective prophage lambda bio11 i lambda ci857 delta h1 or b) the pcr1 plasmid containing the ecori immunity fragment of phage lambda ci857. in addition, gronb bacterial mutants have been isolated at 37 degrees c, as large colony formers in the presence of lambda i lambda ci h434, lambda i ... | 1980 | 6161293 |
| coliphage hk243: biological and physicochemical characteristics. | coliphage hk243 can form plaques on escherichia coli c and k-12, but not b. the plaques are 1-2 mm in diameter and are opaque areas which clear upon exposure to chloroform vapor. during one-step growth, the eclipse and the latent periods are 20 and 30 min, respectively. phage-infected cells continue to produce cell-free plaque-forming units for as long as 80 min after the end of the latent period, although at high multiplicities of infection (moi) most cells lyse. no lysogenic bacteria have been ... | 1980 | 7412594 |
| [bacteriophage lambda integration into host chromosome (biochemistry of int protein and pleiotropic effects of host factors) (author's transl)]. | 1980 | 6243784 | |
| construction and properties of a cole1::tn3-cos lambda plasmid for determining rna polymerase binding sites on cole1 and tn3. | to determine the location of the rna polymerase binding sites on the cole1 plasmid and tn3 transposon, a special hybrid cole1::tn3-cos lambda molecule was constructed which contains the left arm of phage lambda dna and the right lambda terminal fragment. this permits orienting cole1 molecules, since the rna polymerase binding pattern of these two lambda fragments are known to be distinct. cole1 dna contains seven binding sites and tn3 binds three rna polymerases, with some of the latter probably ... | 1980 | 6247244 |
| cloning of the replication gene o of e. coli bacteriophage lambda and its expression under the control of the lac promoter. | the expression of the replication gene o of bacteriophage lambda was put under the control of the lac promoter-operator region integrated into the pbr322 cloning vehicle. the new plasmid pkk104 was introduced into minicells and the o gene induced by isopropyl-beta-thiogalactoside (iptg). the o protein could be identified as a major component in extracts from these cells, in association with the cell membrane fractions. the molecular weight of the o protein in sds gels is about 33 000, and it is ... | 1980 | 6254838 |
| bacteriophage lambda cloning vehicles for studies of genetic recombination. | a pair of bacteriophage lambda cloning vehicles has been constructed for use in studies of genetic recombination. these phages, lambda rva and lambda rvb, have the following properties: (1) each vector has a single hindiii site in the immunity region, at which segments of dna can be inserted. (2) these hindiii sites are flanked by selectable markers with the following phenotypes: spi+/- (fec+/-) to the left, and imm lambda or imm434 to the right. (3) there is essentially no sequence homology bet ... | 1980 | 6254844 |
| the ral gene of phage lambda. i. identification of a non-essential gene that modulates restriction and modification in e. coli. | host controlled restriction in escherichia coli can be relieved by pre-infecting restricting cells with modified lambda helper phages. this process, in which intact unmodified phage genomes are allowed to escape restriction attack, is mediated by a newly identified lambda function called ral. the ral gene has been located by deletion mapping between ciii and n. efficient expression of the ral gene requires the product of the regulator gene n. polyacrylamide gel analysis of the lambda proteins sp ... | 1980 | 6256607 |
| cloning of the exonuclease iii gene of escherichia coli. | overproducers of exonuclease iii (exo iii) were found within a colony bank containing cole1-escherichia coli hybrid plasmids. through the enzymatic ligation of restriction enzyme fragments, the exo iii gene, xth, was transferred to a thermoinducible, integration-proficient lambda phage and to a chimeric cole1-lambda plasmid that was thermoinducible for lambda-directed dna replication. transfer of the xth gene was facilitated by a technique involving prior selection for tn5 insertions into plasmi ... | 1980 | 6260569 |
| expression of prokaryotic genes inserted into cole1 and pvh51 plasmids. | one of the dna fragments obtained from ecori digests of guaa-transducing lambda phage dna contains the intact bacterial guaa gene at its one end and the lambda phage r gene at the other end. this dna fragment, named coslambda-guaa, does not contain promoter-operator regions of the gua operon and of the lambda phage r gene, coslambda-guaa dna fragments were inserted in two different orientations into respective dnas of ecori-cleaved cole1 and pvh151 (= mini cole1). mitomycin c stimulated the guaa ... | 1980 | 6444526 |
| purification and characterization of the integration protein specified by bacteriophage lambda. | 1980 | 6444632 | |
| [adsorption of lambda phage dna onto escherichia coli cells treated with ca2+ ions and onto frozen--thawed bacteria]. | the study of the biologically active tritium-labeled phage lambda dna adosrption on ca2+-treated and frozen--thawed e. coli cells showed the absence of a correlation between the adsorption level and transfection efficiency. thus the infectious phage lambda dna adsorption level does not change, while frozing--thawing of e. coli cells but it increases ten-fold when treating the cells with ca2+ in ice, the transfection efficiency level with this dna being equal for both types of recipients. | 1980 | 6446330 |
| induction of prophage lambda without amplification of reca protein. | the requirement for amplified synthesis of reca protein in the uv-promoted induction of coliphage lambda was studied. we confirmed that a low concentration of rifampicin inhibited specifically the increased synthesis of reca protein after an inducing treatment (satta and pardee, 1978). under these conditions, using an optimal dose of uv, e. coli lysogens were induced, producing active phage. the drug delayed the onset of induction and with increasing concentrations affected the yield of phage, b ... | 1980 | 6446647 |
| pseudovirulent mutants of lambda b221poricasna resulting from mutations in or near oric, the e. coli origin of dna replication. | mutants of the specialized transducing phage lambda b221poricasna have been isolated which form plaques on lambda lysogens. genetic and physical evidence is presented to show that the mutations responsible for the pseudovirulent phenotype map in or near oric, the origin of chromosomal replication in escherichia coli. | 1980 | 6446650 |
| the phage promoter responsible for the expression of the inserted beta-galactosidase gene in bacteriophage lambda plac5. | the lac transducing phage, lambda plac5, carries a segment of the e. coli lac operon on the left side of the b2 region of the lambda phage. in the absence of additional cyclic amp, beta-galactosidase can only be expressed from the phage promoter, and the expression of the inserted lac promoter is suppressed. this phage promoter responsible for beta-galactosidase synthesis is shown to be under the control of the ci and n gene products; however, the repressive action of the cro gene product at hig ... | 1980 | 6446653 |
| transcription antitermination by bacteriophage lambda n gene product. | 1980 | 6447798 | |
| promoter for the establishment of repressor synthesis in bacteriophage lambda. | transcription of the lambda repressor gene (ci) is positively regulated by the phage-encoded proteins cii and ciii. we have isolated and characterized the 5'-terminal region of this rna and shown that it originates at a promoter (pe) located between genes cro and cii. the dna sequence of this promoter shows little homology to other known promoters. initiation of transcription from pe is abolished by the cis-dominant mutations cy; these mutations alter the "-10" and "-35" regions of the promoter. ... | 1980 | 6447872 |
| [genetic properties of phage lambda recombinant molecules. the effect of an inserted fragment on the hybrid yield and recombination with respect to the h- and vir-markers]. | the yield of mature phages in lambda gt-lambda dm34, lambda gt-lambda dm225 and lambda gt-lambda dm234 is 2, 8 and 8 times lower (respectively) as compared to the wild type. the output of hvir-recombinants in lambda gt-lambda dm225 is more than an order lower as compared to the other phages. as distinct from two other hybrids, the decrease in lambda gt-lamba dm225 yield cannot be explained by red-genotype and a shortening of the phage genome as well as the decrease in the output hvir-recombinant ... | 1980 | 6449098 |
| in vitro comparison of initiation properties of bacteriophage lambda wild-type pr and x3 mutant promoters. | the in vitro initiation properties of the pr promoter of bacteriophage lambda and of a pr mutant, x3, were compared. using the abortive initiation reaction, we measured the lags in the approach to a final steady-state rate when dinucleotide synthesis was initiated with rna polymerase. these lags corresponded to the average times required for the formation of transcriptionally active open complexes. by measuring the lags at different rna polymerase concentrations, we could separate open complex f ... | 1980 | 6450417 |
| [effect of coumermycin a1 and nalidixic acid on lambda phage integration and transducing lambdoid phages containing rna-polymerase genes]. | a specific inhibitor of dna gyrase, coumermycin a1, inhibits in vivo the interaction of bacteriophage lambda dna and dna of rifd transducing phages (lambda rifd47 and lambda att80 rifd35) carrying genes rpob and rpoc of rna polymerase. besides, coumermycin a1 inhibits reca-dependent recombination between the bacterial region of rifd phages and a homologous region of escherichia coli chromosome. the integration of transdusing phage dna into the chromosome of reca host is significantly more sensit ... | 1980 | 6450709 |
| thermal (52 degrees c) inactivation and mutagenesis of bacteriophage lambda. | 1980 | 6450895 | |
| regulation of phospholipid biosynthesis in escherichia coli. cloning of the structural gene for the biosynthetic sn-glycerol-3-phosphate dehydrogenase. | the structural gene for the escherichia coli biosynthetic sn-glycerol-3-phosphate (glycerol-p) dehydrogenase gpsa, was transferred from a defective transducing phage (lambda dcyse, gpsa) into the eco ri site of plasmid pmb9 by recombinant dna techniques. the recombinant plasmids suppressed the glycerol-p requirement of gpsa- mutants and strains bearing one such plasmid, pdc2, overproduced the glycerol-p dehydrogenase about 60-fold. the glycerol-p dehydrogenase from a strain bearing the pdc2 was ... | 1980 | 6985897 |
| a dnab analog function specified by bacteriophage p7 and its comparison to the similar function specified by bacteriophage p1. | evidence is presented that bacteriophage p7 specifies an analog of the e. coli dna replication protein, dnab. as in the related bacteriophage p1 (d'ari et al., 1975; ogawa, 1975), in lysogens of p7, the production of the analog protein is repressed and constitutive mutants could be isolated. such constitutive mutants could suppress efficiently the thermosensitivity of several dnab(ts) mutations and also rescue a strain carrying a dnab amber mutation. while neither p7 nor the mutant p1bacban (def ... | 1980 | 6993853 |
| replication control and switch-off function as observed with a mini-f factor plasmid. | mini-f is a fragment of the f plasmid, consisting of 9,000 base pairs, which carries all of the genes and sites required for replicon maintenance and control. its copy number is one to two per chromosome. this plasmid is joined to cole1, whose copy number is 16 to 20. under normal circumstances the composite plasmid replication exhibited cole1 characteristics, maintaining a high copy number. however, when cole1 replication was inhibited by deoxyribonucleic acid polymerase i inactivation, its rep ... | 1981 | 7021532 |
| inducibility of a gene product required for uv and chemical mutagenesis in escherichia coli. | the product of the umuc gene is required for uv and chemical mutagenesis in escherichia coli. by the use of the mud(ap, lac) bacteriophage, we have obtained an operon fusion of the lac structural genes to the promoter/regulatory region of the umuc gene. the strain containing the umuc::mud(ap, lac) fusion was identified on the basis of its uv nonmutability. strains containing this putative null allele of umuc were (i) nonmutable by uv and other agents, (ii) slightly uv sensitive, and (iii) defici ... | 1981 | 7029544 |
| tif-1 mutation alters polynucleotide recognition by the reca protein of escherichia coli. | the requirements for polynucleotide-dependent hydrolysis of atp and for proteolytic cleavage of phage lambda repressor have been examined for both the wild-type (reca+ protein) and the tif-1 mutant form [tif(reca) protein] of the reca gene product. the reca+ and tif(reca) proteins catalyze both reactions in the presence of long single-stranded dnas or certain deoxyhomopolymers. however, short oligonucleotides [(dt)12, (da)14] stimulate neither the protease nor the atpase activities of the reca+ ... | 1981 | 7031642 |
| sos induction and autoregulation of the hima gene for site-specific recombination in escherichia coli. | the hima gene of escherichia coli controls the lysogenization of bacteriophage lambda at the level of catalysis of site-specific recombination and expression of the lambda int and ci genes required for lysogenic development. we have analyzed the regulation of hima by two methods: (i) beta-galactosidase synthesis from a lacz gene inserted into the hima gene and (ii) detection of radioactive hima protein after fractionation by two-dimensional gel electrophoresis. we find that hima- mutations produ ... | 1981 | 6796964 |
| plasmid vectors capable of transferring large dna fragments to yeast. | we have constructed several cloning vectors which can be used in vitro packaging and yeast transformation. these plasmids have been designed for the convenient cloning of large segments of dna and their transfer to yeast. they contain bacterial plasmid dna sequences for replication and selection in escherichia coli, yeast 2-microns plasmid dna sequences or chromosomal replicators and yeast markers necessary for replication and selection in yeast, and the cohesive ends of bacteriophage lambda whi ... | 1981 | 6299664 |
| [low transfecting efficiency of phage lambda ring chromosomes and their fragments formed by membrane nucleases]. | transfection efficiency of a number of lambda dna samples differing in ring to linear molecules ratio was determined. graphic extrapolation to the zero content of linear molecules showed that efficiency of ring molecules did not exceed 5% of that of linear molecules. probably, this difference is caused by more fast penetration of linear molecules into the cell and, therefore, by lower probability of their degradation by cell wall nucleases. fragments of both ring and linear molecules formed by c ... | 1981 | 6453042 |
| evidence that ribosomal protein s10 participates in control of transcription termination. | we report the isolation of an escherichia coli k-12 strain with a mutation, nuse71, that results in a change in ribosomal protein s10. phage lambda fails to grow in hosts carrying the nuse71 mutation because the lambda n gene product is not active. the n product regulates phage gene expression by altering transcription complexes so that they can overcome termination barriers. this suggests that a ribosomal protein is involved in antitermination of transcription. | 1981 | 6453343 |
| purification of bacteriophage lambda o protein that specifically binds to the origin of replication. | by means of a nitrocellulose filter binding assay, dna binding activities among proteins fractionated from extracts of escherichia coli carrying lambda dv have been surveyed. an activity was found that binds specifically to a fragment of 164 base pairs that specifies the lambda replication origin (lambda ori). this activity was not detected in an extract of cells not carrying the lambda dv plasmid. the activity was detected in extracts of cells carrying a hybrid plasmid in which the entire lambd ... | 1981 | 6454055 |
| arrangement of bacteriophage lambda receptor protein (lamb) in the cell surface of escherichia coli: a reconstitution study. | the lamb protein purified in a solution of sodium dodecyl sulfate was assembled into an ordered hexagonal lattice structure with a lattice constant of about 7.8 nm in the presence of lipopolysaccharide. the lamb alone formed aggregates with some lattice structure. however, the regularity of the lattice was only maintained within a very small area. an ordered hexagonal lattice was also formed when the wild-type lipopolysaccharide was replaced by heptoseless lipopolysaccharide, lipid a, and even f ... | 1981 | 6455415 |
| fusion of the lac genes to the promotor for the cytidine deaminase gene of escherichia coli k-12. | phage mu has been inserted into the structural gene for cytidine deaminase (cdd). by the use of phage lambda (lac, mu) the promoter for the cdd gene has been fused to lacz. in these strains lacz expression is regulated by the cytr repressor protein and is therefore induced by cytidine. the fusion strains were used for the isolation of cddo mutants. plaque forming lambda phages carrying the different cdd-lacz fusions were isolated. studies of the cdd-mu strains showed that the cdd gene is transcr ... | 1981 | 6455590 |
| structure and function of the phage lambda att site: size, int-binding sites, and location of the crossover point. | 1981 | 6457725 | |
| effects of recb21, recf143, and uvrd152 on recombination in lambda bacteriophage-prophage and hfr by f- crosses. | the effects of the mutation pairs recb21 recf143 and recb21 uvrd152 on the frequency of genetic recombination were investigated in lambda phage-prophage crosses under homoimmune conditions. to prevent recombinants from being formed by the phage red system, these experiments were performed with phages and prophages carrying red and gam mutations. both spontaneous and damage-induced recombination was measured, the phages being either undamaged or treated with trimethylpsoralen and 360-nm light to ... | 1981 | 6457825 |
| preferential cleavage of phage lambda repressor monomers by reca protease. | 1981 | 6457991 | |
| general method for fine mapping of the escherichia coli k-12 lamb gene: localization of missense mutations affecting bacteriophage lambda adsorption. | lamb is the structural gene for the bacteriophage lambda receptor, a multifunctional protein located in the outer membrane of escherichia coli k-12. we present a method for deletion mapping of any lamb mutations with a recognizable pheno-type. this method involves a transducing phage constructed by in vitro recombination which can also be used for complementation, deoxyribonucleic acid sequence, and in vitro protein synthesis studies with the mutated lamb gene. using this method, we mapped 18 la ... | 1981 | 6458595 |
| direction of bacteriophage lambda dna replication in a thymine requiring escherichia coli k-12 strain. effect of thymidine concentration. | the direction of replication was established for the first round of bacteriophage lambda dna replication in thymine requiring e. coli k-12 cells exposed to different concentrations of thymidine. it was found that a dramatic decrease in the proportion of bidirectionally replicating molecules followed a decrease in the concentration of thymidine. moreover, the rightward mode of replication appears to be exclusively favored in unidirectionally replicating molecules found at low concentrations of th ... | 1981 | 6460985 |
| the nus mutations affect transcription termination in escherichia coli. | the nusa1 and nusb5 mutations in a partial suppression of polarity and thus transcription termination in escherichia coli. as these mutations block the transcription antitermination activity of bacteriophage lambda n gene product, they paradoxically seem to enhance transcription termination at phage termination sites. the rho mutation hdf026 displays almost identical properties. the observations suggest that the nusa and nusb gene products may act as termination factors analogous to rho protein. | 1981 | 6265784 |
| overproduction of the ecorii endonuclease and methylase by escherichia coli strains carrying recombinant plasmids constructed in vitro. | recombinant dna molecules were constructed from the plasmid pil203 and the ecori-fragment of n3 plasmid containing ecorii endonuclease and methylase genes and also a gene for resistance to sulfanilamide. the pil203 plasmid, used as a vector, consisted of the bam hi-ecori-fragment of the plasmid pbr322 conferring resistance to ampicillin and the bam hi-ecori-fragment of lambda phage containing promoters, a thermosensitive mutation in the ci gene and a suppressible amber mutation in the cro gene. ... | 1981 | 6266480 |
| isolation of beta-globin-related genes from a human cosmid library. | a human gene library was constructed using an improved cloning technique for cosmid vectors. human placental dna was partially digested with restriction endonuclease mboi; size-fractionated and ligated to bamhi-cut and phosphatase-treated cosmid vector pjb8. after packaging in lambda phage particles, the recombinant dna was transduced into escherichia coli 1400 or hb101 followed by selection on ampicillin for recombinant e. coli. 150 000 recombinant-dna-containing colonies were screened for the ... | 1981 | 6266915 |
| cosmid cloning and transposon mutagenesis in salmonella typhimurium using phage lambda vehicles. | we have constructed a strain of salmonella typhimurium which contains the malb region from escherichia coli and carries the bacteriophage lambda receptor protein in its outer membrane. phage lambda adsorbs to this strain but cannot grow, thus providing a very useful system for transposon mutagenesis of s. typhimurium using lambda vehicles carrying transposons. this system can also be used for cosmid cloning. | 1981 | 6268936 |
| [artificial tn2551 transposon with replicative properties]. | a hybrid plasmid, pbe10 was constructed. it consists of dnas of rsf2124 (cole1 :: tn3) plasmid and pub110 plasmid of staphylococcus aureus. the latter can be stably maintained in bacillus subtilis. bamhi cleaved pub110 was introduced into the bamhi site of transposon tn3 and the resulting enlarged tn3 (tn2551) was transposed from pbe10 onto phage lambda and than to pmb9 (tc) and rsf1010(sm su) plasmids. restriction and heteroduplex analysis of pmb9 :: tn2551(pbe21) and rsf1010 :: :: tn2551(pbe32 ... | 1981 | 6273258 |
| beta protein of bacteriophage lambda promotes renaturation of dna. | the protein encoded by the red beta gene of bacteriophage lambda was found to promote reannealing of complementary single strands of dna. reannealing activity was optimal at ph 6.0 and required a divalent cation. a threshold temperature of at least 15 degrees c was necessary in order to detect activity. the reaction was linear with time for about 20 min, but the extent of reaction was dependent upon the amount of beta protein added. reannealing of complementary single strands was confirmed by me ... | 1981 | 6273399 |
| construction and characterization of a tufa-lacz fusion coding for an e. coli ef-tu-beta-galactosidase chimeric protein. | a new phage lambda cloning vector was constructed that has a single ecori site upstream from weakly expressed laci-z gene isolated by müller-hill and kania (1974). an ecori fragment containing the complete tufa gene of e. coli was cloned on the vector and the recombinant phage was crossed into the str operon that has tufa as its last gene. subsequent selection gave rise to a tufa-lacz fusion that codes for a chimeric peptide. the fused peptide has a molecular weight of 148,000 and contains 40% o ... | 1981 | 6276696 |
| klebsiella and enterobacter strains derived from hospital infections. ii. occurrence and characterization of r-, lac- and col- plasmids and their clinical-epidemiological significance. | a total of 269 hospital klebsiella strains and 103 hospital enterobacter strains showed 34 and 10 different antibiotic resistance patterns, respectively. among multiple resistant klebsiella and enterobacter strains the ap sm cm tc resistance pattern was the most frequent (k. aerogenes). antibiotic resistant strains carried r-plasmids in 27.5%. the presence of r-plasmids was demonstrable in 2.9% of single antibiotic resistant, in 12.8% of double antibiotic resistant, and in 71.4% of multiple anti ... | 1981 | 7257874 |
| rna splicing mutation in an aberrantly rearranged immunoglobulin lambda i gene. | the mouse cell line mopc 315 is an iga (lambda ii)-producing myeloma. we have studied a derivative of mopc 315 that secretes normal lambda ii chains but no heavy chain. this derivative, mopc 315-26, was found to contain a rearranged lambda i gene in addition to a rearranged lambda ii gene. the rearranged lambda i gene was cloned into bacteriophage lambda dna and its structure was studied. the lambda i gene was found to have arisen by an aberrant recombination event that resulted in a single base ... | 1981 | 6171827 |
| solid-phase sequence analysis of polypeptides eluted from polyacrylamide gels. an aid to interpretation of dna sequences exemplified by the escherichia coli unc operon and bacteriophage lambda. | an approach to sequencing proteins by the solid-phase method combined with isolation of proteins and polypeptides by gel electrophoresis is described. mixtures of proteins or polypeptides resulting from digests are fractionated in the presence of dodecylsulphate in polyacrylamide gels. they are detected with coomassie blue, eluted, selectively reacted with porous glass derivatives and sequenced in their amino-terminal regions with the aid of a new microsequencer. alternatively they can be analys ... | 1982 | 6210528 |
| identity of a chi site of escherichia coli and chi recombinational hotspots of bacteriophage lambda. | 1982 | 6210783 | |
| construction of recombinant lambda phages that carry the e. coli recb and recc genes. | a fragment of the e. coli chromosome including the recc gene has been cloned by in vitro recombinant dna techniques into a phage lambda vector to give the recombinant phage lambda drecc. this was used to derive the phage lambda drecbc by in vivo recombination. on lysogenisation of recb and recc mutants with lambda drecbc wild levels of uv-resistance and recbc dnase activity were restored. infection of e coli with lambda drecbc led to the synthesis of phage-coded proteins of 125 kilodaltons (kd) ... | 1982 | 6211590 |
| a comparison of the requirements for antitumour activity and antibacteriophage lambda activity for a series of non-intercalative dna-binding agents. | a series of non-intercalative dna-binding agents, comprising mainly bisquaternary ammonium heterocyclic compounds, has been found to inhibit strongly the production of bacteriophage lambda following its induction in escherichia coli. the inhibition is much greater than that found with a number of dna intercalating agents, including 9-aminoacridine, ethidium and daunorubicin. the inhibition correlated significantly with antitumour effect, as measured in a life extension assay with l1210 leukaemia ... | 1982 | 6212240 |
| purification of the bacteriophage lambda xis gene product required for lambda excisive recombination. | excision of the lambda prophage from the chromosome of its escherichia coli host requires the products of the two viral genes int and xis. this paper reports a purification of the lambda xis gene product using a complementation assay in which functional xis must be added to purified int and an e. coli-derived host factor extract. excisive recombination between a left (attl) and right (attr) prophage attachment site cloned on the same plasmid dna substrate occurred efficiently under these conditi ... | 1982 | 6213611 |
| cleavage of lambda repressor and synthesis of reca protein induced by transferred uv-damaged f sex factor. | transfer of a uv-damaged f sex factor to a recipient lambda lysogen induces prophage lambda development. under these conditions reca protein synthesis was induced and lambda repressor cleaved, as observed upon direct induction, that is, when the recipient lambda lysogen was directly exposed to uv-light. the efficiency of induction of reca protein synthesis in recipient bacteria which had received an irradiated f-lac factor was about 80% of that measured upon direct induction. we observed the sim ... | 1982 | 6213837 |
| analysis of lambda insertions in the fucose utilization region of escherichia coli k-12: use of lambda fuc and lambda arga transducing bacteriophages to partially order the fucose utilization genes. | escherichia coli k-12 strains have deletions for the normal lambda integration site were lysogenized with bacteriophage lambda at a site within the l-fucose utilization system (fuc). the frequency of lambda integration at this site is approximately 2 x 10(-8) to 5 x 10(-7). studies of the lytic properties of these strains indicated very infrequent cell lysis with a relatively low phage burst size. transductional ability of the phage lysates was found to be normal, comparable to that found in con ... | 1982 | 6214544 |
| mutation and w-reactivation of lambda phage by mitomycin c in the excision-defective escherichia coli. | 1982 | 6216402 | |
| transcriptional termination sites in the b2 region of bacteriophage lambda that are unresponsive to antitermination. | a bacteriophage lambda cloning vector carrying the trp/lacw205 substitution is described. the vector facilitates the fusion in vitro of genetic control signals to the lacz structural gene of escherichia coli. this system was used to define transcriptional termination sites in the lambda b2 region. this region contains termination sites that are unresponsive to the lambda antiterminating proteins pq and pn. | 1982 | 6285144 |
| molecular cloning and amplification of the gene for thymidylate synthetase of e. coli. | the thya gene of escherichia coli, which directs the synthesis of the enzyme thymidylate synthetase, has been subcloned from a recombinant lambda phage (hickson et al., 1982) into the multicopy plasmid pbr325 to give the plasmid ppe245. to identify the thya gene product, the transposon tn1000 was inserted into ppe245 and derivative plasmids isolated that were no longer able to complement thya mutations. when proteins synthesised by these plasmids and by ppe245 were labelled and analysed on sds-p ... | 1982 | 6290329 |
| abelson murine leukemia virus: structural requirements for transforming gene function. | the integrated abelson murine leukemia virus (a-mulv) genome cloned in bacteriophage lambda gtwes.lambda b was used to localize viral genetic sequences required for transformation. comparison of the biological activity of cloned a-mulv genomic and subgenomic fragments showed that subgenomic clones that lacked the 5' long terminal repeat and adjoining sequences (300 base pairs downstream of the repeat) were not biologically active. in contrast, subgenomic clones that lacked the 3' long terminal r ... | 1982 | 6291048 |