Publications

description and properties of bacteriophage lambda vectors useful for the cloning of ecori dna fragments.		1978	352409
selectivity of rna chain initiation in vitro. 2. correlation of 5'-triphosphate-labeled oligonucleotides on polyethyleniminecellulose thin-layer chromatography with rna transcripts of bacteriophage lambda cb2 and t7.	methods are described for the correlation of 5'-terminal oligonucleotides separated by two-dimensional polyethyleniminecellulose thin-layer chromatogrphy with specific rna transcripts made in vitro from dna of phages t7 and lambdacb2. the 5'-terminal oligonucleotides transcribed from dna containing mutations and alterations which affect the rna transcripts from specific promoters were compared with fingerprints of rna from wild type dna. specific rnas were purified on polyacrylamide gels and dig ...	1978	352391
temperature sensitivity in escherichia coli k12: mutants unable to support normal growth of lambda phage at high temperatures.		1978	351930
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
architecture of the outer membrane of escherichia coli. iii. protein-lipopolysaccharide complexes in intramembraneous particles.	in a previous paper (a. verkleij, l. van alphen, j. bijvelt, and b. lugtenberg, biochim. biophys. acta 466:269-282, 1977) we have hypothesized that particles on the outer fracture face of the outer membrane ([formula: see text]), with corresponding pits on the inner fracture face of the outer membrane ([formula: see text]), consist of lipopolysaccharide (lps) aggregates stabilized by divalent cations and that they might contain protein and/or phospholipid. in the present paper the roles of lps, ...	1978	350838
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
replication of colicin e1 plasmid dna in vivo requires no plasmid-encoded proteins.	a derivative of bacteriophage lambda containing a colicin e1 plasmid replicon was constructed by recombinant dna techniques. this phage, lambdacol100, has two functional modes of dna replication; it can replicate via either plasmid or phage replication systems. lambdacol100 has been used to introduce the colicin e1 plasmid replicon into escherichia coli previously treated with chloramphenicol to block protein synthesis. under these conditions, lambdacol100 dna is replicated normally as a colicin ...	1978	346567
major proteins of the escherichia coli outer cell envelope membrane. preliminary characterization of the phage lambda receptor protein.		1978	346375
w-reactivation and w-mutagenesis of gamma-irradiated phage lambda.	uv irradiation of escherichia coli wild-type cells manifested the phenomena of w-reactivation (wr) and w-mutagenesis (wm) of phage lambda irradiated by 60co gamma-rays in broth. wr of gamma-irradiated phage was half as efficient as that of uv-irradiated phage, although the frequency of c mutations in conditions of wr was about the same in both phages. the xtha and recbrecc sbcb mutants were practically identical with wild-type cells in respect of wr and wm of uv- and gamma-irradiated phage. as i ...	1978	345115
[phenomenon of w-reactivation in plasmids].	an analysis of the action of the bacterial repair system on the uv-irradiated pmb9 plasmid has been carried out. it has been shown that the uv-irradiated plasmid is repaired in the bacteria similarly to the dna of bacteriophage (lambda): the effectiveness of the uvr-system is lowered two-three times, and the postreplicativing rec system acts only at low doses of the uv-light. the phenomenon of omega-reactivation is observed both with plasmid and phage dnas.	1978	345103
explanations accounting for transduction by bacteriophage lambda in maltose negative bacteriophage lambda resistant mutants of escherichia coli k-12.	entry of dna from lambda phages particles into lambdarmal- mutants of escherichia coli k-12 is shown to be due to two distinguishable processes. one, residual transduction, results from a low level expression of lamb. the other one, background transduction, is independent of gene lamb. interpretations are presented for these results. it is propos that residual transduction is due to a weak promoter pb3 located within or near the distal part of the gene preceeding lamb in the same operon. it is p ...	1978	345088
packaging of cole1 dna having a lambda phage cohesive end site.	the mechanism of lambda phage-mediated transduction of hybrid colicin e1 dnas of various lengths was studied, and factors influencing the formation of these transducing particles were investigated. the results were as follows: 1. the presence of a cohesive end site of lambda phage (coslambda) on colicin e1 dna was essential for packaging of the dna. 2. packaging of colicin e1 dnas, which carry coslambda with molecular sizes corresponding to 68% of that of lambda phage dna, was observed in the ab ...	1978	345083
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
mechanism of potent mutagenic action of n-methyl-n'-nitro-n-nitrosoguanidine on intracellular phage lambda.		1978	344890
current status of coliphage lambda ek2 vectors.	this article summarizes the rationale behind the design of standardized laboratory tests for certification of bacteriophage lambda ek-2 vector systems. a discussion and description of the six vector systems which have been certified by the u.s. national institutes of health are also included. an appendix describes the officially approved laboratory tests in detail.	1978	344142
insertion sequence is2 associated with int-constitutive mutants of bacteriophage lambda.	we have examined mutations in bacteriophage lambda called int-c, which confer elevated constitutive expression on the int gene for prophage integration. one class of mutations, which map between the b538 and bio386 endpoints, does not appear to be associated with any major chromosomal modification, whereas the second class has the is2 insertion sequence in orientation ii within the region between gene int and the b538 endpoint, all int-c mutations are within gene xis, with the possible exception ...	1977	344135
mutant rna polymerase of escherichia coli terminates transcription in strains making defective rho factor.	we have isolated a rifampicin-resistant mutant of escherichia coli rna polymerase that restores transcription termination in strains with a defective rho protein. in such strains, the mutant rna polymerase terminates transcription at normally rho-dependent sites at the end of the trp operon, in bacteriophage lambda, and within the lac operon. in addition, a strain with this mutant rna polymerase remains viable with an amber mutation in rho, whereas a strain with wild-type rna polymerase does not ...	1978	343107
identification of a host protein necessary for bacteriophage morphogenesis (the groe gene product).	mutations in the groe gene of escherichia coli, which block the correct assembly of the phage lambda head, have been previously described. many groe mutations exert pleiotropic effects, such as inability to propagate phages t4 and t5 and inability to form colonies at 43 degrees. with the help of the ecori and hindiii restrictionenzymes and the appropriate phage vectors, we have constructed two lambda transducing phages, called w3 and h18, that carry the groe+ bacterial gene. upon lysogenization ...	1978	343101
exclusion of bacteriophage t1 by bacteriophage lambda. i. early exclusion requires lambda n gene product and host factors involved in n gene expression.	two modes of exclusion of t1 by lambda are distinguished. "early" exclusion depends on gene n, but not on gene q. it is at least partially ineffective against t1am23. "late" exclusion depends on gene q and effects t1am23 as well as t1+. early exclusion is a direct effect of n gene product, rather than n gene being required for the expression of some other lambda gene. three host mutations, gron, nusa, and nusb, known to interfere with lambda replication by affecting n gene expression, also inter ...	1978	342726
[competence in escherichia coli cells. v. interaction of the competence factor with the cells].	some trends of the interaction of the competence factor with the cells are described on the model of phage lambda transfection. it is shown that this process depends on the composition of the recipients growth media, the temperature regime in the interaction processand on the concentration of the competence factor and the recipient cells. the preliminary treatment of the recipient by edta (0.0001 m), cacl2 (less than 0.02 m), mgcl2 (less than 0.01 m), and nacl (less than 0.01 m) resulted in the ...	1978	342337
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
isolation of ultravirulent mutants of phage lambda.		1978	341501
production of a functional eukaryotic enzyme in escherichia coli: cloning and expression of the yeast structural gene for imidazole-glycerolphosphate dehydratase (his3).	a cloned segment of yeast dna containing the structural gene for imidazoleglycerolphosphate dehydratase (d-erythro-imidazoleglycerolphosphate hydro-lase, ec 4.2.1.19) is transcribed and translated in escherichia coli with sufficient fidelity to produce functional enzyme. this segment of yeast dna was isolated as a viable molecular hybrid of bacteriophage lambda (lambdagt-sc2601) which complements a nonrevertible hisb auxotroph of e. coli lacking dehydratase activity. the equivalent segments of d ...	1977	341150
overproducing arac protein with lambda-arabinose transducing phage.	escherichia coli infected with bacteriophage lambda-arabinose transducing phage were tested as sources of arac protein. infection of cells with such phage produces an intracellular concentration of arac protein up to 100 times that present in wild-type e. coli, apparently resulting from fusion of the arac gene to bacteriophage lambda promoters. lysates from these phage-infected cells may be fractionated to yield another 100-fold enrichment in arac activity so that the total enrichment is 10,000- ...	1977	340930
purification and properties of a lambda operator-binding protein which is expected to be autorepressor (tof protein) from e. coli carrying lambdadv plasmid.	in order to study the mode of action of the tof gene product, which is an "autorepressor" of the bacteriophage lambda and plasmid lambdadv, we have purified a dna-binding protein which is specifically produced in bacteria carrying lambdadv. this protein possesses characteristics expected for the product of the tof gene, since it is produced under conditions where ci-repressor is not made, and since it binds to ol and or operators on the lambda phage genome. the molecular weight of the native pro ...	1977	340920
isolation and characterization of mutants of escherichia coli deficient in induction of mutations by ultraviolet light.	mutants of e. coli defective in susceptibility to uv-induction of mutations were isolated by direct screening for their uv nonmutable phenotype (umu-). screening of about 30,000 mutagenized clones of a uvr-b derivative of ab1157 yielded six umu- strains. the mutants can be classified into three groups by the location of the mutations, umua, umub and umuc. mutations umua and umub are, respectively, mapped close to lexa and reca genes and mutations at both loci partially reduce uv mutagenesis. the ...	1977	340898
repressor and int synthesis of bacteriophage lambda in the e. coli host mutant er437.	analysis of lambda phage infection of the host mutant er437 by sds polyacrylamide gel electrophoresis and autoradiography has revealed altered expression of repressor and integration function (int). we show that in this host int as well as repressor synthesis is not dependent upon the lambdaciii gene product in the usual manner, nor is their synthesis turned off in the normal way.	1977	340886
the thirteenth colworth medal lecture: the construction in vitro and exploitation of transducing derivatives of bacteriophage lambda.		1977	340298
structure and assembly of bacteriophage lambda.		1977	340151
dna replication--bacteriophage lambda.		1977	340149
integration and excision of bacteriophage lambda.		1977	340148
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
transcription of bacteriophage lambda dna in vitro using purine nucleoside 5'-[gamma-s]triphosphates as affinity probes for rna chain initiation.		1978	339949
[lysogenization and induction of phage lambda (author's transl)].		1977	339279
isolation and characterization of the biotin genes of escherichia coli k-12.	dna containing the biotin gene cluster, bioabfcd, of e. coli k-12 has been isolated from the ecori cleavage products of lambdabiot124-10 phage dna and subsequently characterized by electron microscopic studies. the biotin-dna fragment obtained after ecori cleavage of the lambdabiot124-10 dna measures 18.7% lambda dna length (approx. 9000 base pairs). in addition to the biotin genes, it contains 4.75% and 3.08% lambda phage dna at the left and right end-points of the bioabfcd cluster, respectivel ...	1977	338422
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
an improved bacteriophage lambda vector: construction of model recombinants coding for kanamycin resistance.	an attenuated bacteriophage lambda has been prepared for proposed use as an ek2 vector. this phage, designated lambdagt vir jam27 zam718-lambdab' can accomodate up to 11.10(6) daltons of foreign dna inserted through eco ri ends. the virulence mutations and nin 5 reduce the frequency of lysogen and/or plasmid formation. the mutations jam27 and zam718 require a suppressor in the bacterial host. the phage recombination functions contained in the ecorilambdac fragment have been deleted, and only the ...	1977	338417
block between early and late transcription of coliphage lambda in minicells.		1977	337653
the isolation of restriction fragments containing the primary and secondary (galt) bacterial att sites of phage lambda.		1977	337652
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
function of the tof gene product in modifying chemical stability of trp messenger rna synthesized from the pl promoter of lambda trp phage.	the trp operon translocated into the early region of phage lambda can be transcribed under the control of two promoters, the authentic trp promoter (ptrptrp mrna) and the pl promoter of the n gene (pltrp mrna) (imamoto and tani, 1972; ihara and imamoto, 1976a). pltrp mrna is stabilized with time after infection: at early times after infection chemical degradation of pltrp mrna is two-fold slower than for ptrptrp mrna, while at later times the stabilization of pltrp mrna is almost total. the stab ...	1977	337123
genetic studies of hybrids between coliphage lambda and salmonella phage p22: genetic analysis of the p22-lambda hybrid class.	p22-lambda hybrids which retain the protein coat of p22 have been isolated and characterized into two types. type 1 hybrids which have the c through o-p genes of lambda are unable to grow lytically on salmonella typhimurium. on the other hand, type 2 hybrids which contain only the c region of lambda, plated on s. typhimurium. both hybrid types retained the generalized transducing and antigenic conversion capabilities of p22.	1977	337122
normal expression of the viral gene n interferes with growth of bacteriophage lambda in escherichia coli 15t-.		1977	337114
recombination pathway specificity of chi.	chi in phage lambda is a genetic element increasing the rate of recombination in its vicinity. chi activity requires the wild-type functions of both the reca and the recb genes of e. coli. in terms of the pathway concept for recombination, chi is active in the recbc pathway and inactive in the red, rece., and recf pathways.	1977	336458
involvement of dna-dependent rna polymerase in a reca-independent pathway of genetic recombination in escheria coli.	recombinant dna molecule of phage lambda formed in escherichia coli in the presence of chloramphenicol and/or rifampin can be assayed by their biological activity. reca- cells were found to be capable of forming recombinant lambda phage dna in the presence of chloramphenicol. the relatively high reca-independent recombination observed in this system contrasts with the relatively low reca-independent recombination when recombinant phage particles rather than recombinant dna are titrated. formatio ...	1977	333450
insertion of dna carrying ribosomal protein genes of escherichia coli into charon vector phages.	dna fragments from lambdaspc1 and lambdafus2, carrying ribosomal protein genes from escherichia coli, were inserted into lambda phage vectors charon 3 and charon 4. eight of the resulting clones were characterized by agarose gel electrophoresis of ecori digests, analytical cscl equilibrium centrifugation, and electron micrographic analysis of heteroduplexes. in each case, the identity, order, and orientation of each cloned fragment was determined. in all, 8 of the 12 ecori fragments of lambdafus ...	1977	332692
[in vitro production of of a vector molecule composed of dna from lambda phage and a plasmid with the determinant for resistance to tetracycline].		1977	332477
a simplified method for mapping deletion/substitution mutants of bacteriophage lambda.		1977	332007
circular dimers of a lambda dna in infected, nonlysogenic escherichia coli.	covalently closed circular dimers of phage lambda dna have been found in escherichia coli infected with lambda. these dimers can be formed by either the lambda red or int systems, by a nonrecombinational replicative mechanism requiring the activity of the lambda o and p genes or by joining of the cohesive ends. dimers mediated by the e. coli rec system have not been observed. those formed by the int system often result from recombination between different dna molecules; however, the red-mediated ...	1977	331660
formation of recombinant dna of bacteriophage lambda by reca function of escherichia coli without duplication, transcription, translation, and maturation.	genetic recombination of phage lambda dna mediated by rec function of escherichia coli was studied in the absence of duplication, transcription, translation, and maturation. cells were jointly infected with double amber mutants, lambda d-f-i and lambda s-r-, and incubated in the presence of chloramphenicol and rifampin. the am+ recombinant dna molecules formed within the cell were detected by in vitro packaging as viable recombinant phages. this system was used to measure the recombination activ ...	1977	331071
genetic and physiological control of host cell lysis by bacteriophage lambda.	the timing of host cell lysis at the end of the lytic cycle of phage lambda is under complex control. the lambda s protein stimulates lysis. another physiological system, the lysis regulator, inhibitis lysis from occurring prematurely. the effects of a series of phage and bacterial mutations on these controls are described. they show that the lambda rex gene plays a role in regulating lysis under suboptimal growth conditions. in certain mutant cells, and especially under anaerobic culture condit ...	1977	330879
the effect of a drug-resistance factor on recombination and repair of dna in escherichia coli k12.	the presence in recipient strains of escherichia coli k12 of the plasmid r46 greatly reduced the yield of recombinants from crosses with several hfr strains and virtually abolished the formation of recombinants by pi transduction without, however, significantly affecting the transfer of the f prime from a strain carrying fgal. the r46 plasmid had paradoxical effects on mutability: it appeared to enhance the yield of mutants following irradiation with ultraviolet ligh but it reduced the number of ...	1977	330823
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
cro regulatory protein specified by bacteriophage lambda. structure, dna-binding, and repression of rna synthesis.	the cro protein specified by bacteriophage lambda is a repressor of the genes expressed early in phage development and is required for a normal late stage of lytic growth. we have purified cro protein to virtual homogeneity and analyzed its structure and properties as a dna-binding protein and repressor of rna synthesis. to confirm that the protein is the product of the cro gene, we have also shown that a missense mutation in the cro gene leads to a product that is more temperature- and salt-sen ...	1977	330523
threonyl-transfer ribonucleic acid synthetase from escherichia coli: subunit structure and genetic analysis of the structural gene by means of a mutated enzyme and of a specialized transducing lambda bacteriophage.	threonyl-transfer ribonucleic acid synthetase (thrrs) has been purified from a strain of escherichia coli that shows a ninefold overproduction of this enzyme. determination of the molecular weight of the purified, native enzyme by gel chromatography and by polyacrylamide gel electrophoresis at different gel concentrations yielded apparent molecular weight values of 150,000 and 161,000, respectively. polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate yields a single prot ...	1977	330505
state of the gal-transducing hybrid phage lambda ci857nin5h424gal+ genome in klebsiella pneumoniae m5a1.		1977	330392
interrelationship of the phage lambda receptor protein and maltose transport in mutants of escherichia coli k12.		1977	329879
inactivation and proteolytic cleavage of phage lambda repressor in vitro in an atp-dependent reaction.	we have reproduced in vitro the inactivation of bacteriophage lambda repressor that occurs in vivo when a lambda lysogen is treated with agents such as ultraviolet radiation that attack dna. atp and a divalent cation are required for the inactivation reaction. the ind- repressor is insensitive to the inactivation mechanism. a proteolytic cleavage of repressor accompanies inactivation in vitro, as it does in vivo.	1977	329277
repression of inducible enzyme synthesis in a mutant of escherichia coli k 12 deleted for the ptsh gene.	the genome of lambda phage with thermosensitive repressor was inserted into the pts region of the escherichia coli chromosome. this lysogenic culture possessed the pts1 phenotype at 30 degrees c. a mutant strain with a deletion covering the ptsh gene was isolated after a prophage curing procedure. the deletion nature of the pts mutation was confirmed in genetical and biochemical experiments. the deletion covered a small fragment of the bacterial genome not extending in the ptsi and lig genes. th ...	1977	329116
bacteria with defective rho factors suppress the effects of n mutations in bacteriophage lambda.	a prediction based on the model for n-gene function of bacteriophage lambda proposed by roberts (1971) is confirmed by showing that a lambdan- double mutant is able to grow in strains of e. coli with defective rho transcription termination factors. the burst sizes for lambdan- in these strains range from 5 to 24% the burst sizes for lambdan+ in the same strain. this low level of suppression is also evident in the levels of synthesis of the lambda exonuclease and is consistent with other evidence ...	1977	329106
transcription of insertion elements is1 and is2 in vitro.	insertion elements is1 and is2 integrated within the gal operator-promoter region, an is1 element in gene galt and insertions is1 and is2 integrated in the xyciiop region of phage lambda were transcribed in vitro with e. coli rna-polymerase. the insertion elements are transcribed exclusively by polymerase molecules started at the gal promoter and the lambdapr promoter respectively. no promoter exists on is1 or is2 which can be recognized by rna-polymerase in the pure in vitro transcription syste ...	1977	329104
morphogenesis of bacteriophage lambda deletion mutants. ii. escherichia coli mutants which prevent maturation of short genomes.		1977	328900
morphogenesis of bacteriophage lambda deletion mutants. i. abnormal head-related structures produced in normal escherichia coli.		1977	328899
initiation of the dna replication of bacteriophage lambda in escherichia coli k12.		1977	328896
inhibition of beta-galactosidase synthesis in escherichia coli after infection with different dna and rna phages.	infection of escherichia cooi with t1, t2r+, t3 and t4 phages leads to an immediate inhibition of beta-galactosidase synthesis. similar results were obtained with the virulent mutant of phage lambda. the degree of inhibition of beta-galactosidase synthesis depends on the time delay between the addition of the inducer and the phage particles, and on the amount of phage dna, which has penetrated into the host cell. rna phage ms2 exhibited no inhibitory effect on enzyme synthesis.	1977	328356
[interaction of the isolated dna of lambda phage with spheroplasts of e. coli treated with sturine].	the method of centrifugation in sucrose density gradient (30-55%) of the spheroplast membrane preparations treated and untreated with sturine and infected with phage lambda dna demonstrated that sturine, treatment increased the phage lambda dna absorption three-fold. about 50% of the lambda dna molecules adsorbed by spheroplasts are bound with the cytoplasmic membrane of spheroplasts treated with sturine; 50% of the lambda dna molecules are bound with the cell wall membrane on the sturine-untrea ...	1977	328079
r factor types found in salmonella typhimurium and escherichia coli isolated from calves in a confined environment.	typing of r factors by genetic properties was done with salmonella typhimurium and escherichia coli isolated from calves on a feedlot where epizootics of clinical or subclinical calf salmonellosis had repeatedly occurred during 5 years. forty-nine r factors from s typhimurium were fi- (no fertility inhibition) and spp- (no restriction against phage lambda vir). twenty-three (46.9%) of them belonged to compatibility group ialpha and the remainder were nontypable. fourteen r factors from e coli be ...	1977	327875
[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
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
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
amber mutants in the o gene of bacteriophage lambda are not efficiently complemented in the absence of phage n function.		1977	325882
genetic characterization of plasmid formation by n- mutants of bacteriophage lambda.		1977	325881
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
mutagenesis of lambda phage: 5-bromouracil and hydroxylamine.	mutagenesis by 5-bromouracil of lambda phage to clear plaque formers does not depend on the reca function of the host e. coli cell or on the red function of the phage. pretreatment of the host cells with ultraviolet light does not affect bromouracil mutagenesis of the adsorbed phage. mutagenesis by hydroxlamine to clear plaque formers takes place at a high level in reca- host cells, and is not changed by preirradiation of of rec+ (wild type) hosts with ultraviolet light. thus, bromouracil and hy ...	1977	325384
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
[dna modification in vitro by e. coli c and e. coli mre 600 dna-cytosine-methyltransferases: increased resistance of bacteriophage lambda dna to the rii restriction system].		1977	322977
ek2 derivatives of bacteriophage lambda useful in the cloning of dna from higher organisms: the lambdagtwes system.	a derivative of bacteriophage lambda has been modified and tested together with an appropriate host system to meet the criteria of ek2 biologic containment for cloning dna from higher organisms. in this report certain of the safety features are summarized and some of the tests carried out to confirm the containment properties of the vector are described. the cloning efficiency of this system, together with available gene purification and hybrid screening technology, indicate that it can be used ...	1977	322278
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
effects of ribosomal mutations on the read-through of a chain termination signal: studies on the synthesis of bacteriophage lambda o gene protein in vitro.	in a dna-dependent protein-synthesizing system that contains streptomycin-sensitive ribosomes, lambda dna directs the synthesis of two proteins that are products of the o gene. the larger is produced as a result of read-through of a uga termination codon. in the system containing streptomycin-resistant ribosomes this read-through protein is not synthesized, indicating that the mutational alteration in the ribosomal protein s12 restricts the read-through. the mutant ribosomes also fail to synthes ...	1977	322139
induction of protein x in escherichia coli.	certain treatments that damage dna and/or inhibit replication in e. coli have been reported to induce synthesis of a new protein, termed protein x, in reca+ lexa+ strains. we have examined some of the treatments that might induce protein x and we have, in particular, tested the hypothesis of gudas and pardee (1975) that dna degradation products play an essential role in the induction process. we confirmed that uv irradiation, nalidixic acid treatment, or thymine starvation result in protein x sy ...	1977	321932
uv-induced alleviation of k-specific restriction of bacteriophage lambda.	a partial release of k-specific restriction of phage lambda grown in escherichia coli c was observed when e. coli k strains ab1157 (having wild-type repair of uv-produced dna damage) and ab1886 (uvra) were irradiated with uv light before infection. the effect occurred in ab1886 at lower uv fluences than it did in ab1157. little or no release of restriction was observed when ab2463 (reca) or ab2494 (lex-1) was used. such release of restriction appears to be another of the uv-induced phenomena ass ...	1977	321803
the elongation factor tu coded by the tufa gene of escherichia coli k-12 is almost identical to that coded by the tufb gene.	radioactive elongation factor tu coded by either the tufa or the tufb gene of escherichia coli k-12 was isolated from cells incubated with a mixture of radioactive amino acids after infection with the defective lambda phage particles that carry either of these genes. two-dimensional chromatographic analyses of tryptic digests of the tufb gene product revealed about 50 radioactive spots. these same spots plus an additional one were also found in tryptic digests of the tufa gene product. furthermo ...	1977	321450
tn402: a new transposable element determining trimethoprim resistance that inserts in bacteriophage lambda.	we have found that the trimethoprim resistance determinant of the incp plasmid r751 (jacob et al., 1977; jobanputra and datta, 1974) transposes to bacteriophage lambda. we call this transposable element tn402.	1977	321437
induced reactivity of uv-damaged phage gamma in e. coli k12 host cells treated with aflatoxin b1 metabolites.	the metabolites of aflatoxin b1, the most potent hepatocarcinogen so far known, promote in e. coli k12 cells the reactivation of phage lambda damaged by ultraviolet (uv) radiation. this reactivation process is error prone; 25% of the phage dna lesions are repaired, but mutagenesis, scored as clear plaque formation, is increased as much as 10-fold. such reactivation of uv-damaged phage lambda, which occurs in wild-type and in uvra but not in reca bacteria, is inducible: phage reactivation is obta ...	1977	320463
antitermination and absence of processing of the leftward transcript of coliphage lambda in the rnaase iii-deficient host.		1977	320345
isolation and characterization of lambda pleu bacteriophages.	in the escherichia coli lysogen hfrh73 described by shimada et al. (1973), none of the enzymes coded for by the leucine operon is synthesized due to an insertion of phage lambda into cistron leua. the orientation of lambda in the chromosome is ara leudcb lambda jan leua. after heat induction of the lysogen, plaque-forming transducing phages of two types are formed at low frequency. one type (e.g., lambda pleu9) transduces leud, leuc, and leub strains to prototrophy. the other type (e.g., lambda ...	1977	320178
a mutant of escherichia coli showing constitutive expression of the lysogenic induction and error-prone dna repair pathways.	a mutant of e. coli (designated the sts mutant) has been isolated in which the phage induction and error-prone dna repair pathways appear to be expressed constitutively without the cells having received an inducing signal. phage lambda was not able to lysogenize this mutant, whereas a noninducible mutant of lambda, lambdaciind-, known to synthesize a repressor that is insensitive to the induction mechanism, lysogenized it normally. this result suggested that normal phage repressor was synthesize ...	1977	319458
lambdoid phages that simplify the recovery of in vitro recombinants.	derivatives of phage lambda are described for use as vectors for fragments of dna generated with the hindiii and ecori restriction enzymes. with some vectors, hybrid molecules are recognised by a change from a turbid to a clear plaque morphology resulting from the insertion of a fragment of dna into the lambda gene coding for the phage regressor. other vectors contain a central, replaceable fragment of dna which imparts a readily recognisable phenotype. this central fragment may include either a ...	1977	319344
genetic inversion in the formation of an hfr strain from a temperature-sensitive f' gal strain.	an hfr strain (pb15) that carries a duplicated copy of the galactose operon genes flanking the integrated sex factor is unusually stable since it does not show excision of the repeated deoxyribonucleic acid segment. the right-hand galactose operon is in the normal orientation. deletion mutations that eliminate the right-hand galactose genes, the sex factor, and some of the left-hand operon have been isolated. mutants believed to have their left-hand galactose operon inverted were able to be indu ...	1977	318642
evidence against the reversion of mutation in the haemophilus influenzae phage hp1c1 by preinfection treatment of host cells or phage with mnng.	n-methyl-n'-nitrosoguanidine (mnng) causes reversion of a temperature-sensitive mutation in a bacteriophage of haemophilus influenzae if exposure to the mutagen takes place after infection but before lysis. however, neither pre-infection treatment of the phage dna, host cells, or both will cause reversion. the reasons for this are discussed in relation to the somewhat different results in the escherichia coli lambda phage system and in relation to error-prone repair and replication processes.	1978	306062
cell-cycle-associated rearrangement of inverted repeat dna sequences.	inverted repeat dna sequences of caulobacter crescentus have been isolated, characterized, and cloned in a bacteriophage lambda vector. both whole populations and individual clones of these sequences were hybridized to restriction endonuclease-generated fragments of chromosomal dna isolated from cells that were in different stages of the cell cycle. some inverted repeat dna sequences were observed to hybridize to different regions of the chromosomal dna isolated from the morphologically and bioc ...	1979	293718
molecular model for the transposition and replication of bacteriophage mu and other transposable elements.	a series of molecular events will explain how genetic elements can transpose from one dna site to another, generate a short oligonucleotide duplication at both ends of the new insertion site, and replicate in the transposition process. these events include the formation of recombinant molecules which have been postulated to be intermediates in the transposition process. the model explains how the replication of bacteriophage mu is obligatorily associated with movement to new genetic sites. it po ...	1979	287033
the lambda repressor contains two domains.	papain digestion of the lambda phage repressor produces two fragments that are relatively resistant to further digestion. one includes the amino terminus (residues 1-92) and the other the carboxyl terminus (residues 132-236). calorimetry shows that the amino-terminal fragment denatures near 50 degrees c and that the carboxyl-terminal fragment denatures near 70 degrees c. intact repressor undergoes two denaturations, one near 50 degrees c and another near 70 degrees c. these and other data show t ...	1979	287002
n-independent leftward transcription in coliphage lambda: deletions, insertions and new promoters bypassing termination functions.	lambda mutants capable of n-independent red-gam gene expression were isolated by selecting fec+ plaque-forming derivatives of lambda n+ nutl- (fec-) strains. in addition to true nutl+ reversions, three classes of second-site mutations were identified: (1) ninl deletions that remove a region containing either tl1 or both tl1 and tl2 termination signals, or only a small region (defining the rut site) just upstream from tl1, (2) new constitutive promoters that map just upstream from the tl2 termina ...	1979	286866
construction and some properties of packageable plasmid f.	a derivative of plasmid f which is packageable in lambda phage coat was constructed using techniques of in vitro recombination. this plasmid is composed of three dna fragments generated by restriction enzyme ecori: a minif fragment (fragment f5 of f'lac) which is able to replicate autonomously, a dna fragment from staphylococcus plasmid that carries the beta-lactamase gene, and a portion of guaa (b) transducing lambda phage dna carrying lambda cohesive ends (cos site) along with almost all the ...	1979	286145
location of the regulatory site for establishment of repression by bacteriophage lambda.	during the lysogenic response to infection by bacteriophage lambda, the phage-specified cii and ciii proteins provide for the coordinate establishment of repression and integration of the viral dna. one critical regulatory function of cii/ciii is an activation of synthesis of the ci protein, the repressor that maintains lysogeny. the mechanism and site for regulation of the ci gene by cii/ciii have been a subject of controversy. the two principal hypotheses for cii/ciii action are: initiation of ...	1979	284327
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
interaction of bacteriophage lambda repressor with nonoperator dna containing single-strand gaps.	in direct binding assays, purified lambdaind+ repressor displayed high affinity for nonoperator dna containing single-strand gaps. its affinity for this same dna but completely double-stranded, nicked, or denatured was considerably lower. in contrast, purified lambdaind- repressor had 1/10th the affinity for the gapped dna, a level comparable to that of purified lac repressor. in the presence of limiting amounts of ind+ repressor, nonoperator dna containing gaps could be shown to compete effecti ...	1978	282604
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
the cloning of mouse globin and surrounding gene sequences in bacteriophage lambda.		1978	277326