Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 |
| chromosomal integration of phage lambda by means of a dna insertion element. | phage lambdacam112, which contains the chloramphenicol resistance transposon tn9 and has a deletion of attp and the int gene, will lysogenize escherichia coli k-12. prophage integration occurs at different chromosomal sites, including lacy and malb, but not at attb. all lambdacam112 prophages are excised from the chromosome after induction but with various efficiencies for different locations. heteroduplex analysis of lambdaplacz transducing phages isolated from a lacy::lambdacam112 prophage rev ... | 1978 | 274736 |
| nucleotide sequences of the separate origins of synthesis of bacteriophage g4 viral and complementary dna strands. | bacteriophage g4 has physically separated origins of synthesis of its viral and complementary dna strands. chain termination and "plus and minus" dna sequencing methods have been used to obtain the nucleotide sequence of these two origins. the unique origin at which the complementary dna strand is initiated has located in the untranslated region between genes f and g. this sequence, which has considerable secondary structure, contains a stretch which is complementary to the rna primer that is ob ... | 1978 | 274698 |
| mechanism of action of the cro protein of bacteriophage lambda. | the mechanism of action of cro protein was probed by measuring its ability to protect dna against methylation by dimethyl sulfate and its effect on transcription in vitro. the cro protein binds to the same three sites in the right operator (or) of bacteriophage lambda dna as does the lambda repressor. dimethyl sulfate protection experiments reveal major groove contacts for both proteins, and cro protein protects from methylation a subset of those purines protected by lambda repressor. these expe ... | 1978 | 273909 |
| discrete length classes of dna depend on mode of dehydration. | the length of double-stranded coliphage lambda dna, as determined by electron microscopy using the benzyldimethylalkyl ammonium chloride technique, depends on the mode of dehydration. the freeze-dried dna form is the longest (16.5 micron), whereas dehydration in methanol (15.9 micron) or in ethanol (three forms: 15.2 micron, 13.9 micron, and 12.4 micron) results in progressively shorter molecules. these measured lengths of the freeze-dried, methanol-dehydrated, and shortest ethanol-dehydrated fo ... | 1978 | 273234 |
| cloning specific segments of the mammalian genome: bacteriophage lambda containing mouse globin and surrounding gene sequences. | we have developed a general approach to the cloning of specific segments of the mammalian genome that involves a two-step purification of ecori fragments of mammalian dna and their in vitro insertion into a suitably constructed ek2 derivative of bacteriophage lambda. the combination of fragment purification, exclusion of parental-type recombinants, and simple phage screening techniques permits the isolation of virtually any gene segment for which there is an identifying hybridization probe. we i ... | 1977 | 270684 |
| characterization of the integration protein of bacteriophage lambda as a site-specific dna-binding protein. | the int protein specified by bacteriophage lambda is required for the recombination event that integrates the viral dna into the host genome at its specific attachment site. using a dna-binding assay, we have partially purified the int protein and studied some of the features of its binding specificity and regulation. the dna-binding activity is attributed to int protein because the activity is eliminated by a nonsense mutation or a deletion in the int gene, and is rendered thermolabile by tempe ... | 1977 | 266191 |
| assembly of biologically active proheads of bacteriophage lambda in vitro. | bacteriophage lambda dna can be packaged in vitro into preformed proheads to generate plaque-forming units. this complex set of reactions is initiated when lambda dna is mixed with the product of the phage a gene, and proheads. because proheads are an essential early reactant, the system has potential as an assay for the formation of biologically active proheads. when extracts of cells infected with certain lambda head mutants (for example, b--, c--, nu3--, and e--) are used as the prohead donor ... | 1977 | 265585 |
| a thermostable sequence-specific endonuclease from thermus aquaticus. | a sequence-specific endonuclease, taq i, of novel specificity has been partially purified from an extreme thermophile, thermus aquaticus. the enzyme cleaves bacteriophage lambda dna at many (greater than 30) sites and bacteriophage psix174 rf dna at 10 sites. the enzyme is active at temperatures up to 70 degrees. the cleavage sites on psix174 rf dna have been mapped. the sequence recognized and cleaved by taq i has been shown to be the symmetrical tetranucleotide: (formula: see text). | 1977 | 265518 |
| initiation of genetic exchanges in lambda phage--prophage crosses. | when escherichia coli k-12 (lambda) lysogens were infected with lambda phages, genetic exchanges between phage and prophage occurred at low frequencies (less than 0.1% between the markers p3 and p80), but at frequencies above 1% if the infecting phages were first treated with the photosensitizing agent 4,5',8-trimethylpsoralen and 360 nm light. exchanges were induced by psoralen damage at about the same frequency in wild-type lysogens and in those carrying recb(-), recc(-), recf(-), or lexa(-), ... | 1977 | 264683 |
| nucleotide sequence of cro, cii and part of the o gene in phage lambda dna. | a nucleotide sequence comprising 960 base pairs of bacteriophage lambda dna has been determined. the sequence includes the entire genes of the regulatory proteins cro and cii, and part of the o gene, together with control elements for their transcription and translation. the right-hand boundaries of the lambdaimm434 and lambdaimm21 substitutions and the cy42 mutation have been located. | 1978 | 264238 |
| gene transfer to human cells: transducing phage lambda plac gene expression in gmi-gangliosidosis fibroblasts. | genetic information from the bacterium escherichia coli was transferred to human cells by means of the specialized transducing phage lambda plac carrying the bacterial z gene for the enzyme beta-galactosidase (geta-d-galactoside galactohydrolase, ec 3.2.1.23). as recipient cells, cultured skin fibroblasts from a patient with generalized gangliosidosis (gmi-gangliosidosis type i) characterized by a severe deficiency of beta-galactosidase activity were used. the deficient human cells were incubate ... | 1975 | 242006 |
| a deoxyribonuclease of diplococcus pneumoniae specific for methylated dna. | a deoxyribonuclease specific for methylated dna was isolated from diplococcus pneumoniae. the enzyme, an endonuclease, degrades dna for escherichia coli to fragments of average molecular weight about half a million; it forms discrete fragments from phage lambda dna. methyl-deficient e. coli dna is not attacked, neither is dna from micrococcus radiodurans, which contains no methylated adenine or cytosine. nor is dna from d. pneumoniae or phage t7 attacked. however, dna from m. radiodurans, d. pne ... | 1975 | 236309 |
| characterization of lambda escherichia coli hybrids carrying chemotaxis genes. | molecular cloning techniques were used to construct hybrid escherichia coli lambda phage and isolate col e1 factors that carried the cheb region of the e. coli genome. the products of these genes were examined by using a series of deletions in the phage to stimulate specific polypeptide synthesis in ultraviolet-irradiated cells and by using col factor to program protein synthesis in minicells. seven flagellar related polypeptides were synthesized. three of these with apparent molecular weights o ... | 1977 | 233725 |
| [integration of lambda phage (author's transl)]. | 1979 | 233426 | |
| use of the lambda phage promoter pl to promote gene expression in hybrid plasmid cloning vehicles. | 1979 | 232223 | |
| in vitro insertion of the lambda attachment site into the plasmid rp4. | the region of the phage lambda chromosome containing the attachment site (p.p') and the genes int and xis, excised by the action of endonuclease r.ecori, has been inserted into the unique site for that enzyme on the promiscuous conjugative plasmid, rp4, generating the recombinant plasmid rp4att lambda. transformants containing the hybrid plasmid were recognised by their ability to allow efficient lysogenization by phage lambda b2 (weil and signer, 1968; echols et al., 1968) containing the mutant ... | 1979 | 231725 |
| phage lambda receptor chromosomes for dna fragments made with restriction endonuclease i of bacillus amyloliquefaciens h. | 1979 | 231662 | |
| a new host-vector system allowing selection for foreign dna inserts in bacteriophage lambda gtwes. | an improved vector (lambda gtwes.t5-622) for ecori fragments has been derived from ek2 vector lambda gtwes.lambdab' by replacing the lambda b fragment with two identical 1.1 md fragments from the pre-early region of bacteriophage t5. the new vector has two advantages which facilitate elimination of parental-type recombinants in an in vitro recombination experiment. firstly, the 1.1 md insert is too small to be re-inserted into lambda gtwes in a single copy. secondly the 1.1 md t5 fragment carrie ... | 1979 | 231542 |
| nonspecific cleavage by restriction endonuclease r . eco k of bacteriophage lambda-dna. | 1979 | 231440 | |
| the form of the dna substrate required for excisive recombination of bacteriophage lambda. | 1979 | 229232 | |
| search for a dna gyrase in mammalian mitochondria. | incorporation of labeled deoxynucleoside triphosphates into mtdna by isolated rat liver mitochondria has been shown previously to reflect dna replication. we have used this system to seek evidence for a mtdna gyrase. coumermycin, novobiocin, nalidixic acid, and oxolinic acid are known to be inhibitors of escherichia coli gyrase, to inhibit e. coli dna replication, to abolish colicin e1 replication, and to depress the supercoiling of phage lambda dna, the last two via inhibition of the dna gyrase ... | 1979 | 227861 |
| deoxyribonucleic acid and outer membrane: strains diploid for the oric region show elevated levels of deoxyribonucleic acid-binding protein and evidence for specific binding of the oric region to outer membrane. | we have recently reported that part of the chromosomal deoxyribonucleic acid (dna) of escherichia coli is associated with the outer membrane fraction and that an outer membrane protein having a molecular weight of 31,000 probably is involved in this association (h. wolf-watz and a. norqvist, j. bacteriol. 140:43-49, 1979). we have now found that f' merodiploid strains containing two copies of the dna between bglb and ilv have increased levels of this protein and an increased amount of dna in the ... | 1979 | 227835 |
| nicking-closing activity associated with bacteriophage lambda int gene product. | integrative recombination of bacteriophage lambda requires the action of the protein int, the product of the phage int gene. in this paper we show that highly purified int relaxes supercoiled dna. the association of this nicking-closing activity with int is shown by: (i) the cosedimentation of nicking-closing and recombination activities of purified int, (ii) the parallel inactivation of the two activities in purified int by both heat and a specific antiserum, and (iii) the alteration of both ac ... | 1979 | 226979 |
| integrative recombination of bacteriophage lambda: requirement for supertwisted dna in vivo and characterization of int. | 1979 | 226309 | |
| persistence of phage lambda dna in genomes of mouse cells transformed by lambda-carrying sv40 vectors. | to test the suitability of simian virus 40 (sv40) dna as a vector for inserting dna segments into the chromosomes of mammalian cells, an ecori-a fragment of bacteriophage lambda dna was covalently joined to a fragment of sv40 dna and used to transform mouse cells in culture. three independent, morphologically transformed clones were obtained that were positive for sv40 t-antigen by immunofluorescence staining. dna from each transformant was examined by restriction enzyme analysis and found to co ... | 1979 | 225241 |
| dna replication proteins of escherichia coli and phage lambda. | 1979 | 225103 | |
| 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 |
| molecular cloning of polyoma virus dna in escherichia coli: lambda phage vector system. | the biological activity of recombinant phage and recombinant phage dna containing monomeric or dimeric polyoma dna inserts was examined in mice and cultured mouse cells. recombinant preparations containing a single copy of viral dna were invariably noninfectious; molecules containing a dimeric polyoma dna insert were at least seven orders of magnitude less infectious than polyoma virions after parenteral inoculation. no infection was detected with any recombinant preparation after oral administr ... | 1979 | 217088 |
| cloning of herpes simplex type 1 dna fragments in a bacteriophage lambda vector. | dna isolated from defective and nondefective virions of herpes simplex type 1 (hsv-1) (strain patton) was digested with restriction endonucleases, and the resulting dna fragments were inserted in the ek2 coliphage vector lambdagtwes . lambdab. the recombinant dna was encapsidated in vitro under p4 maximum containment conditions. these lambda-hsv1 hybrids were purified and amplified, and the dna was isolated in the p4 facility. dna, free of viable phage and bacteria, was removed from p4 condition ... | 1979 | 216076 |
| antagonists of dna gyrase inhibit repair and recombination of uv-irradiated phage lambda. | intracellular lambda dna (from edta-sensitive tandem duplication phages) was extracted from infected rec+ bacteria and scored for infectivity and recombination (loss of duplication) by transfection of reca recb spheroplasts and subsequent assay for edta resistance. when phage development was blocked by repressor or by antibiotics (chloramphenicol and/or rifampin), the apparent recombination frequency was about 0.1% above the background value for reca infections. prior irradiation of the phage gr ... | 1978 | 212734 |
| a spectroscopic and electron microscopic examination of the highly condensed dna structures formed by denaturation in mg(clo4)2. | 1. thermal denaturation in 1.5 m mg(clo4)2 of the dna from bacteriophage lambda results in four well-separated subtransitions, as monitored by the accompanying increase in absorbance. the midpoint of the hyperchromic spectrum is significantly lowered compared to either 1.5 m mgcl2 or 3.0 m naclo4. 2. the first two subtransitions are associated with the melting of the a . t-richest regions of the lambda dna, as revealed by electron micrographs following fixation with formaldehyde. 3. commencing ... | 1978 | 207326 |
| characterization and classification of virus particles associated with hepatitis a. ii. type and configuration of nucleic acid. | virus particles banding at 1.34 g/ml in cscl and sedimenting at 160s in sucrose gradients were isolated from fecal specimens of patients suffering from hepatitis. in the presence of 4 m urea and about 90% formamide, these particles released linear nucleic acid molecules of the kinked appearance characteristic of single-stranded rna or single-stranded dna. they could be distinguished from the nucleic acid of phage lambda added to the preparation as a marker for double-stranded configuration. expe ... | 1978 | 206731 |
| on the structure of the deo operon of escherichia coli. | a characterization of a specialized transducing lambda phage for the deo operon (lambdaddeo), and some composite cole1-deo plasmids is given in this paper. this includes localization of the rsmai, rhind/iii, rbami, and recori sensitive sites. the deo genes have been localized by construction of composite cole1-deo plasmids. using the dna fragments, obtained by digestion with recori and rhindiii, respectively, as templates in an in vitro protein synthesizing system, it has been possible to give t ... | 1977 | 200836 |
| ribonucleic acid polymerase mutant of escherichia coli defective in flagella formation. | escherichia coli k-12 mutants that are resistant to bacteriophage chi, defective in motility, and unable to grow at high temperature (42 degrees c) were isolated from among those selected for rifampin resistance at low temperature (30 degrees c) after mutagenesis with n-methyl-n'-nitro-n-nitrosoguanidine. genetic analysis of one such mutant indicated the presence of two mutations that probably affect the beta subunit of ribonucleic acid (rna) polymerase: one (rif) causing rifampin resistance and ... | 1977 | 199575 |
| physical and genetic characterization of deletion mutants of simian virus 40 constructed in vitro. | mutants of simian virus 40 (sv40), with deletions ranging in size from fewer than 3 to 750 base pairs located throughout the sv40 genome, were obtained by infecting cv-1p cells with linear sv40 dna and dna of an appropriate helper virus. the linear dna was obtained by complete cleavage of closed circular dna with hae ii or bam hi endonuclease or partial cleavage with either hae iii endonuclease or nuclease s1, followed, in some cases, by mild digestion with phage lambda 5' -exonuclease. the foll ... | 1977 | 198579 |
| a gal region mutant that requires camp for growth on galactose in an adenyl cyclase negative (cya delta) background. | strains of escherichia coli k12 that contain a deletion of the adenyl cyclase gen (cya delta), required for the synthesis of cyclic adenosine-3';5' monophosphate (camp), grow on galactose-containing minimal medium. a mutant was isolated that grows on this medium only if camp is added. the mutation (designated galp20) is linked to the gal operon region as determined by both generalized transduction with bacteriophage p1 and specialized transduction with bacteriophage lambda. studies with galp20 c ... | 1977 | 190530 |
| escape synthesis of beta-galactosidase under the control of bacteriophage lambda. | 1976 | 190407 | |
| construction of hybrid viruses containing sv40 and lambda phage dna segments and their propagation in cultured monkey cells. | this paper describes the successful construction and propagation of a transducing animal virus. a segment of dna approximately 2 kilobases (kb) in length was removed from the late region of the sv40 genome by sequential cleavages with hpa ii and bam hi endonucleases (at 0.735 and 0.13, respectively, on the sv40 dna map). a segment of about 1.5 kb of lambda phage containing ori (the origin of lambda dna replication), the two structural genes cii and cro, and four transcriptional promoters, was in ... | 1976 | 189942 |
| dna gyrase: an enzyme that introduces superhelical turns into dna. | relaxed closed-circular dna is converted to negatively supercoiled dna by dna gyrase. this enzyme has been purified from escherichia coli cells. the reaction requires atp and mg++ and is stimulated by spermidine. the enzyme acts equally well on relaxed closed-circular colicin e1, phage lambda, and simian virus 40 dna. the final superhelix density of the dna can be considerably greater than that found in intracellularly supercoiled dna. | 1976 | 186775 |
| structure of a defective simian virus 40 genome bearing an operator from bacteriophage lambda. | we examined further the physical structure of the simian virus 40 (sv40) and bacteriophage lambda dna sequences in an sv40-lambda hybrid that had been propagated in monkey kidney cells. the sv40 vector portion of the hybrid, which was a small fragment isolated from a reiteration mutant of sv40, contained the site for initiation of sv40 dna replication. electron microscope heteroduplex and restriction endonuclease analyses revealed a tandem duplication of the sv40 vector segment linked to a 2,300 ... | 1976 | 184298 |
| the restriction endonucleases in bacillus amyloliquefaciens n strain. substrate specificities. | two species of restriction endonuclease were isolated by gel filtration and deae-cellulose chromatography from a cell-free extract of bacillus amyloliquefaciens (b. subtilits) n strain; a lower molecular weight endonuclease (endonuclease r.bamni) and a higher molecular-weight one (endonuclease r.bamnx). both of them required only mg2+ for their activities. endonuclease r.bamnx introduced a larger number of site-specific scissions in excherchia coli phage lambda dna that endonuclease r.bamni did. ... | 1976 | 182257 |
| the adsorption of coliphage lambda to its host: effect of variations in the surface density of receptor and in phage-receptor affinity. | 1976 | 181582 | |
| suppression of polarity of insertion mutations in the gal operon and n mutations in bacteriophage lambda. | bacterial mutations (psua and psu) known for their ability to suppress the polarity on nonsense mutations are shown to suppress the polarity of certain insertion mutations in the gal operon. the short insertion, is1 (800 nucleotide pairs), is about 15 to 50% suppressed, whereas longer insertions, is2 (1,400 nucleotide pairs), and is3 (1,200 nucleotide pairs), are not. some of the polarity suppressor mutations (psu-1, psu-2, and psu-3) are at least partially permissive for n-gene mutations (n7 an ... | 1976 | 181361 |
| multiple steps during the interaction between coliphage lambda and its receptor protein in vitro. | 1976 | 180667 | |
| construction and propagation of a defective simian virus 40 genome bearing an operator from bacteriophage lambda. | a 2400 base pair dna segment containing the leftward operator (ol) of phage lambda was covalently joined in vitro to a fragment of simian virus 40 (sv40) dna harboring the sv40 replication origin. the recombinant molecule was propagated in the presence of helper wild-type sv40 dna in monkey kidney cells and partially cloned by an infectious center procedure. after propagation in monkey cells and purification, the hybrid dna could be distinguished from wild-type sv40 dna by its shortened length ( ... | 1976 | 177971 |
| properties of adenyl cyclase and cyclic adenosine 3',5'-monophosphate receptor protein-deficient mutants of escherichia coli. | several spontaneous cya and crp mutants of escherichia coli have been selected as clones simultaneously resistant to phage lambda and nalidixic acid and characterized. both cya and crp mutants have been found to grow as cocci with increased doubling times. they have increased resistance to some mutagens (methylmethanesulfonate, ultraviolet light, gamma rays), antibiotics (nalidixic acid, ampicillin), phages (lambda, t6), sublethal heat and hypotonic shock, and decreased resistance to neutral det ... | 1976 | 173710 |
| [rna fragments rich in g and a nucleotides obligatory for in vitro dna replication of phages phi-x 174 and lambda]. | evidence was presented that in vitro conversion of single-stranded dna of phage phi x 174 to the double-stranded replicative form by partially purified dna-dependent dna polymerase i requires a specific rna fragment acting as primer (25-50 nucleotides). rna fragments highly rich in nucleotides a and g were obtained by partial degradation of e. coli m 500 sho-r ribosomal rna with pancreatic ribonuclease. they become covalently bound to the newly synthesized dna chain of the replicative form of ph ... | 1975 | 172251 |
| selective effects of mgcl2 and temperature on the initiation of transcription at lac, gal, and lambda promoters. | we have studied the effect of mg2+ on the formation of transcription preinitiation complexes (open complexes) at two adenosine 3':5'-monophosphate (cyclic amp)-cyclic amp receptor protein (crp)-dependent promoters (lac and gal) and two phage lambda promoters, pl and pr. mg2+ strongly interferes with open complex formation at the lac and gal promoters, partially inhibits the lambda pr promoter, and is without effect on the lambda pl promoter. mutations in the lac and gal promoters can affect the ... | 1975 | 170282 |
| operator-promoter functions in the threonine operon of escherichia coli. | the prophage curing properties of secondary-site lysogens of coliphage lambda have been studied. the site of integration in the original lysogen (l79) is within the ooerator-promoter region of the thr operon. as a result, expression of the thr enzymes is reduced, and the strain is a leaky threonine auxotroph. heat pulse curing of strain l79 and a thr+ lysogenic revertant (l79-20) showed that heat pulse curing of both lysogens was int and xis dependent and occurred by correct excisions of the pro ... | 1975 | 170244 |
| the action of colicin e2 on supercoiled lambda dna.ii. experiments in vitro. | an in vitro system has been developed to test whether colicin e2 possesses dnase activity. purified colicin e2 preparations introduced one single-strand scission in supercoiled lambda phage dna. glycerol gradient fractionation of colicin e2 supports the association of in vitro action with in vivo cell-killing activity. colicin e2 preparations also attacked superhelical sv40 dna yielding open circles and fragments and single-stranded fd dna molecules causing one or more endonucleolytic breaks. th ... | 1975 | 167801 |
| pleiotropic effects of a dna adenine methylation mutation (dam-3) in escherichia coli k12. | the dam-3 mutation results in a five-fold reduction in the number of 6-methyl-adenine (6-mea) residues in the dna of e. coli k12 or phage lambda. the dna of phage fd appears to be devoid of 6-mea when propagated on dam-3 bacteria. the phenotypic differences between dam-3 and dam+ bacteria include: (i) increased free phage in lysogenic dam-3 cultures, (2) increased sensitivity to methyl methanesulfonate (mms), (3) inviability of dam-3 lex-i strains, (4) lower molecular weight of dna in dam-3 bact ... | 1975 | 167279 |
| the nucleotide sequence in the promoter region of the gene n in bacteriophage lambda. | the sequence of 18 nucleotides in the region preceding the initiation of transcription of the gene n of bacteriophage lambda has been determined to be as follows (see article). the basic approach used for the sequence determination involved escherichia coli dna polymerase i-catalyzed elongation of the octadecanucleotide primer, dt-c-a-g-t-g-c-g-t-c-c-t-g-c-t-g-a-ru, possessing the appropriate polarity and nucleotide sequence corresponding to the 5' end of the gene n transcript. following hybridi ... | 1975 | 167018 |
| oligo(a) not coded by dna generating 3'-terminal heterogeneity in a lambda phage rna. | an rna species from escherichia coli infected with phage lambda was purified by hybridization to lambda 1-strand dna and shown to have variable length. this variability was due to a variable number of adenylate residues attached to the 3' end of the molecule. pancreatic rnase treatment of the rna-dna hybrid removed the 3'-terminal adenylate residues, generating a homogeneous rna molecule terminating with -up. the results indicate the presence of adenylate residues not coded by the dna template a ... | 1975 | 167007 |
| regulation of phage lambda development with the growth rate of host cells: a homeostatic mechanism. | 1975 | 166503 | |
| intergration of the receptor for bacteriophage lambda in the outer membrane of escherichia coli: coupling with cell division. | induction of the synthesis of the receptor for phage lambda is obtained by adding maltose and adenosine 3'-5'-cyclic monophosphate to glucose grown cells of escherichia coli. bacteria induced for a short period of time were infected with a high multiplicity of phage lambda , and examined under the electron microscope. only a fraction of the bacteria were seen to have adsorbed a large number of phage particles. the majority of such bacteria had a constriction indicating formation of a septum, and ... | 1975 | 164434 |
| w reactivation is inefficient in repair of the bacterial chromosome. | uv-inducible "sos" processes associated with w reactivation of phage lambda were studied for their effect on repair of lambda prophage integrated in the bacterial chromosome. for this purpose, lambda c1857 ind red-lysogens were used. these lysogens, although non-inducible by uv light, can be induced by raising the temperature from 30 degrees to 42 degrees. if the w reactivation processes are involved in repair of the bacterial dna, when the lysogens are incubated at 30 degrees after uv exposure ... | 1979 | 161343 |
| structural studies of bacteriophage lambda heads and proheads by small angle x-ray diffraction. | 1979 | 161330 | |
| convergent transcription in bacteriophage lambda: interference with gene expression. | 1979 | 161329 | |
| a simple technique for the isolation of deletion mutants of phage lambda. | we describe a simple technique for isolating deletion mutants of phage lambda and use it to dissect a cloned fragment of foreign dna. the technique is based on our previous finding that the normally essential product of lambda head gene d is dispensible for phage growth if the dna content of the phage is less than 82% that of lambda wild-type (sternberg and weisberg, 1977). a significant fraction of the few phage that form plaques when a d amber mutant is plated on a nonsuppressing host contains ... | 1979 | 161244 |
| some properties of site-specific and general recombination inferred from int-initiated exchanges by bacteriophage lambda. | the site-specific recombination at the attachment site for prophage integration might proceed by two general mechanisms: (1) a concerted reaction without a free intermediate; (2) a sequential mechanism differing from typical general recombination only by an inability of the cross-strand intermediate structure to migrate into the region of nonhomology adjacent to the attachment site. the blocked-migration model predicts frequent genetic exchange in the int xis region near the attachment site if i ... | 1979 | 161242 |
| 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 |
| effect of experimental magnetic storm on the production of lambda phage. | 1. sharp fluctuation of the intensity of the vertical component of the mf amounting to +/- 0.1 oe changing the sign over each 3 min causes variability of both lysogenic and indicator strains of e. coli. this testifies to an extremely low threshold of their magnetic susceptibility and to biological importance of fluctuations of natural parameters of the geomagnetic field as an ecological factor of the environment. 2. a change in the intensity of the vertical component of the mf, not any higher th ... | 1979 | 160920 |
| dna-directed in vitro synthesis of proteins involved in bacterial transcription and translation. | the in vitro synthesis of elongation factor (ef)-tu (tufb), the beta beta' subunits of rna polymerase, ribosomal proteins l10 and l12 directed by dna from the transducing phage lambda rifd 18, ef-tu (tufa), ef-g, and the alpha subunit of rna polymerase directed by dna from the transducing phage lambda fus3 has been investigated in a crude and a partially defined protein-synthesizing system. proteins l10 and l12 are synthesized in the partially defined system almost as well as in the crude system ... | 1979 | 160561 |
| dna from recombinogenic lambda bacteriophages generated by arl mutant of escherichia coli is cleaved by single-strand-specific endonuclease s1. | when propagated on arl strains (a subclass of escherichia coli hyper-rec mutants), lambda "red-" duplication phages accumulated an enhanced potential for recombination. the physical properties of the recombinogenic phages thus obtained ("arl-" phages) were similar to those of phages grown on arl+ bacteria. however, arl- phage dna was cleaved by endonuclease s1 under conditions such that the nuclease is specific for single-stranded dna;dna from control phages was s1-resistant. the number of s1 si ... | 1979 | 160560 |
| gene expression of an escherichia coli ribosomal rna promoter fused to structural genes of the galactose operon. | the promoter region of the rrnb ribosomal rna gene of escherichia coli has been ligated within the epimerase gene (gale) of the galactose operon in a lambda phage vector. the recombinant lambda phage has been characterized by restriction mapping and assays of both galk (galactokinase) gene activity and galactose messenger rna hybridization. in such lyosgens, expression of the fused galactose operon occurs as a function of growth rate in a manner characteristic of ribosomal rna gene expression an ... | 1979 | 160557 |
| transcription and membrane attachment of bacteriophage lambda dna in the absence of n function in the e. coli sua 1 mutant. | in the polarity suppressor strain psua 1, we observe a partial n independence of both transcription and dna-membrane attachment for a lambda nn mutant. these results, in agreement with the genetical data reported by dambly et al. (1976), suggest that the n product and rho factor are involved in the same process but may not interact directly. | 1979 | 160492 |
| loss of rac locus dna in merozygotes of escherichia coli k12. | dna-dna hybridization was used to demonstrate that the substituted dna in the bacteriophage lambda rece (formerly called lambda reverse) is homologous to dna at the rac locus in escherichia coli. strains that are rac- do not contain appreciable amounts of this dna, and it is lost from a rac+ episome (f' 123) after transmission to a rac- recipient. this is consistent with the proposal that the rac locus contains a cryptic prophage (low, 1973). | 1979 | 160489 |
| transposition mutagenesis of bacteriophage lambda: a new gene affecting cell lysis. | 1979 | 160463 | |
| a comprehensive molecular map of bacteriophage lambda. | physical and genetic mapping of deletion mutations has been correlated with the available molecular sizes of the lambda gene products and the dna base sequence to construct a comprehensive molecular map of the phage lambda genome. the physical length of the dna making up the left arm from the cos site through gene j is not sufficient to account in a nonoverlapping manner for all the proteins of the sizes reported to be coded, especially in the nu1--c region. in the right arm all the coding capac ... | 1979 | 160360 |
| 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 |
| specificity of the bacteriophage lambda n gene product (pn): nut sequences are necessary and sufficient for antitermination by pn. | we have cloned the nutr site together with the tr1 site of bacteriophage lambda in the e. coli galactose operon to examine whether the lambda promoter sequences pr and pl are involved in the recognition specificity of the lambda n gene product (pn). we first constructed a derivative of plasmid pbr322 in which the expression of the tetracycline genes (tet) is controlled by the gal promoter (pgal). this new plasmid contains a unique hind iii site between pgal and tet into which the nutr and tr1 si ... | 1979 | 160286 |
| differential modes of processing and decay for the major n-dependent rna transcript of coliphage lambda. | 1979 | 160127 | |
| 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 |
| uvm mutants of escherichia coli k12 deficient in uv mutagenesis. ii. further evidence for a novel function in error-prone repair. | uvm mutants of escherichia coli k12 selected for defective uv reversion induction have previously been reported to differ considerably from the uv-reversion-less reca and lexa mutants with regard to survival or mutagenic response to uv, x-rays and alkylating agents. in the present study, the phenotypic characterization of uvm mutants was extended to investigate several cellular processes which also may be related to or involved in uv mutagenesis. like reca and lexa mutations, the uvm mutations e ... | 1979 | 160001 |
| in vivo methylation of bacteriophage phi x174 dna. | a mutant (designated mec(-)) has been isolated from escherichia coli c which has lost dna-cytosine methylase activity and the ability to protect phage lambda against in vivo restriction by the rii endonuclease. this situation is analogous to that observed with an e. coli k-12 mec(-) mutant; thus, the e. coli c methylase appears to have overlapping sequence specificity with the k-12 and rii enzymes; (the latter methylases have been shown previously to recognize the same sequence). covalently clos ... | 1979 | 159962 |
| orientation-dependent recombination hotspot activity in bacteriophage lambda. | 1979 | 159958 | |
| dna without supertwists can be an in vitro substrate for site-specific recombination of bacteriophage lambda. | 1979 | 159956 | |
| control of rightward transcription in coliphage lambda by the regulatory functions of phage genes n and cro. | 1979 | 159560 | |
| stimulation of t of function and pl-proximal transcription by the n gene product of coliphage lambda. | 1979 | 159559 | |
| clustering of prm- mutations of bacteriophage lambda in the region between 33 and 40 nucleotides from the cl transcription start point. | 1979 | 159558 | |
| sigma subunit of escherichia coli rna polymerase affects the function of lambda n gene. | a new class of escherichia coli mutants, referred to as grn, has been isolated by localized mutagenesis. these mutations affect the sigma subunit of dna-dependent rna polymerase (ribonucleoside 5'-triphosphate:rna nucleotidyltransferase, ec 2.7.7.6) by abolishing the expression of the lambda n gene, and they are closely lniked to dnag in the order dnag-grn-uxaa. detailed study of one such mutant, grn1, yielded the following results: (i) grn1 is a single mutation and the mutant cell shows cold-se ... | 1979 | 159460 |
| transcription promotes reca-independent recombination mediated by dna-dependent rna polymerase in escherichia coli. | the rpo-mediated recombination of phage lambda takes place independently of the reca function and is promoted by dna-dependent rna polymerase of escherichia coli [ikeda, h. & kobayashi, i. (1977) proc. natl. acad sci. usa 74, 3932--3936]. the crossovers were particularly frequent to the ciii-n and n-cii regions which are transcribed actively. to determine whether the transcription process required for the recombination is the initiation step or the chain elongation step, we have examined the eff ... | 1979 | 159459 |
| cloning of integrated moloney sarcoma proviral dna sequences in bacteriophage lambda. | we have identified integrated proviral dna sequences of m1 and ht-1 isolates of moloney sarcoma virus (musv) in ecori digests of transformed mink cell genomic dna and have cloned these fragments in bacteriophage lambda. both the lambda-ht1 phage recombinant, containing a 12.3-kilobase musv pair (kb) fragment, and the lambda-m1 phage recombinant, containing a 7.0-kb fragment, possess full copies of the sarcoma viruses along with 5' and 3' host flanking sequences. the musv proviral dna sequences, ... | 1979 | 159456 |
| cloning of the structural gene (ompa) for an integral outer membrane protein of escherichia coli k-12. | the gene (ompa) for the major outer membrane protein ii* from escherichia coli k-12 has been cloned on a 5-megadalton ecori fragment by using phage lambda as vector. the gene is expressed during the lytic cycle of the recombinant phage and the insoluble membrane-bound protein was detected in phage plaques with a simple radioimmunoassay. transfer of the ecori fragment into plasmid psc101 and expression in a host lacking protein ii* led to overproduction of protein ii* and decreased production of ... | 1979 | 159455 |
| interactions between dna-bound repressors govern regulation by the lambda phage repressor. | the lambda phage repressor binds cooperatively to the three sites in the right operator (o(r)) according to the following pattern. if the dna is wild type, o(r)1 and o(r)2 are filled coordinately because of interactions between repressor dimers bound to these two sites. site o(r)3 is filled only at higher repressor concentrations. in contrast, if o(r)1 is mutant, o(r)2 and o(r)3 are filled coordinately because of interactions between repressors bound to these sites. in this case, the affinity of ... | 1979 | 159452 |
| [the use of bacteriophage lambda fragments in the construction of plasmid vectors for gene cloning. included: restriction map of lambda dna (author's transl)]. | 1979 | 159438 | |
| mutants of escherichia coli that do not contain 1,4-diaminobutane (putrescine) or spermidine. | strains of escherichia coli k12 have been constructed which do not contain any of the polyamines normally present in a wild type strain, namely, 1,4-diaminobutane (putrescine) and spermidine. this phenotype arises as a consequence of the assembly into these strains of deletion mutations in spea (arginine decarboxylase), speb (agmatine ureohydrolase), spec (ornithine decarboxylase), and sped (adenosylmethionine decarboxylase). the polyamine-deficient strains grow indefinitely in the absence of po ... | 1979 | 159306 |
| lambda transducing bacteriophage carrying deletions of the argcbh-rpobc region of the escherichia coli chromosome. | deletions in the rpobc region have been transferred to phage lambda and characterized in detail by genetic, structural, and functional tests. we thus extend and confirm knowledge of the organization of this part of the chromosome. the new phages are useful tools for studying the genes for the bacterial transcription and translation machinery. | 1979 | 159290 |
| location of a cole1 deoxyribonucleic acid region that affects the plaque-forming ability of lambda-cole1 hybrid bacteriophage. | the plaque-forming ability of a hybrid phage between plasmidcole1 and phage lambda carrying amber mutations in genes o and p was inhibited by the presence of cole1 in suppressor-deficient escherichia coli cells. cole1 deoxyribonucleic acid regions concerned with this inhibition were examined by using various deletion and transposon insertion derivatives of cole1, and it was found that the presence of the deoxyribonucleic acid region extending between 420 and 613 base pairs upstream from the init ... | 1979 | 159288 |
| escherichia coli rna polymerase binding and initiation of transcription on fragments of lambda rifd 18 dna containing promoters for lambda genes and for rrnb, tufb, rplc,a, rplj,l, and rpob,c genes. | promoters of genes for bacteriophage lambda and for escherichia coli ribosomal rna (rrnb), elongation factor tu (tufb), ribosomal proteins l11 (rplk), l1 (rpla), l10 (rplj), and l7/l12 (rpll), and rna polymerase subunits beta (rpob) and beta' (rpoc) were studied by use of two types of filter binding assays which measured e. coli rna polymerase binding and initiation of transcription on restriction fragments of lambda rifd 18 dna. the dna fragments selectively retained on filters were eluted, con ... | 1979 | 159206 |
| [characteristics of bacteriophage lambda and p1 modification-restriction in escherichia coli strains controlled by factor r124]. | the specifities of restriction of bacteriophages p1 and lambda controlled by r plasmids in escherichia coli have been investigated. the isogenic strains harbouring the plasmids pas26 coding for restriction endonuclease r.ecori, r245 coding for restriction endonuclease r.ecorii and and r124 have been investigated in the present work. modification-restriction controlled by r124 has been found to differ in specificity from those controlled by r245 and pas26. frequencies of restriction of bacterioph ... | 1979 | 159204 |
| interaction of int protein with specific sites on lambda att dna. | we have studied the interaction of highly purified int protein with dna restriction fragments from the lambda phage attachment site (attp) region. two different dna sequences are protected by bound int protein against partial digestion by either pancreatic dnaase or neocarzinostatin. one int binding site includes the 15 bp common core sequence (the crossover region for site-specific recombination) plus several bases of sequence adjoining the core in both the p and p' arms. the second int-protect ... | 1979 | 159130 |
| the rat serum albumin gene: analysis of cloned sequences. | the rat serum albumin gene has been isolated from a recombinant library containing the entire rat genome cloned in the lambda phage charon 4a. preliminary r-loop and restriction analysis has revealed that this gene is split into at least 14 fragments (exons) by 13 intervening sequences (introns), and that it occupies a minimum of 14.5 kilobases of genomic dna. | 1979 | 158758 |
| electron microscopic analysis of transcription: mapping of initiation sites and direction of transcription. | an electron microscope technique is described that allows rapid characterization of transcription in vitro. dna is transcribed with escherichia coli rna polymerase in vitro, and the rna is hybridized to its template. measurement of the resulting transcription r-loop molecules allows accurate mapping of transcription initiation sites (promoter sites) and analysis of the direction and rate of transcription and the level of transcription from each initiation site. the two major early promoters pr a ... | 1979 | 158757 |
| [new transducing phage with rna polymerase beta- and beta'-subunit genes derived from a hybrid phage lambda att80: isolation, genetic analysis and physical mapping]. | a hybrid lambda att 80 phage with the genetic structure lambda (a-j) phi 80 (att-int-xis) imm lambda..ci857s7 is shown to be a convenient vector for creating transducing phages. on the one hand, the restriction analysis indicates that it has 3 restriction sites for ecori in comparison with 5 and 9 sites for parental phages lambda and phi 80 respectively. on the other hand, its buoyant density is less than that of phage lambda and under centrifugation it is easier separated from the phage transdu ... | 1979 | 158560 |
| heteroduplex regions in unduplicated bacteriophage lambda recombinants. | 1979 | 158480 | |
| regulatory structure of the insertion region of bacteriophage lambda. | 1979 | 158466 | |
| site-specific recombination of bacteriophage lambda: the role of host gene products. | 1979 | 158465 | |
| integrative recombination of bacteriophage lambda: in vitro study of the intermolecular reaction. | 1979 | 158463 |