Publications

in vitro genetic recombination of bacteriophage lambda.	dna of bacteriophage lambda recombines in a cell-free extract prepared from an induced escherichia coli lysogen of bacteriophage lambda. the assay for recombination in vitro takes advantage of the ability of such an extract to package lambda dna and to assemble complete phage particles. for example, when lambda dna that has been extracted from phage with the immunity of 434 is added to an extract, infectious lambda imm 434 particles are produced. the precursor dna molecule in this packaging reac ...	1974	4526306
bacteriophage lambda having ecori endonuclease sites only in the nonessential region of the genome.	a derivative of lambda b221 that has lost by mutation all ecori restriction sites has been isolated by alternative growth on restrictive and nonrestrictive strains. it has an efficiency of plating equal to 1 on the restrictive strain. genetic cross of this bacteriophage with lambda plac5 imm21 gave rise to recombinants of intermediate restricting ratios. the analysis of the ecori endonuclease-cleaved dna by polyacrylamide gel electrophoresis, compared with the genetic results, has permitted iden ...	1974	4530273
control elements in the dna of bacteriophage lambda.		1974	4545512
separation and analysis of promoter sites in bacteriophage lambda dna by specific endonucleases.		1974	4546908
letter: the yield of single-strand breaks in the dna of bacteriophage lambda irradiated extra- and intracellularly with gamma-rays in oxic and anoxic conditions.		1974	4548053
functional abnormality of lambda phage particles from complemented fii-mutant lysates.		1974	4413519
physical mapping of the trp endpoint in the n-tl segment of phage lambda trpe-a.		1974	4415067
protein cleavage in bacteriophage lambda tail assembly.		1974	4415352
rec-mediated recombinational hot spot activity in bacteriophage lambda. i. hot spot activity associated with spi-deletions and bio substitutions.	in order to survey the distribution along the bacteriophage lambda chromosome of rec-mediated recombination events, crosses are performed using conditions which block essentially all dna synthesis. one parent is density-labeled and carries a genetic marker in the left terminal lambda gene (a), while the other parent is unlabeled and carries a genetic marker in the right terminal lambda gene (r). both parents are deleted for the lambda recombination genes int and red, together with other recombin ...	1974	4415484
rec-mediated recombinational hot spot activity in bacteriophage lambda. ii. a mutation which causes hot spot activity.	crosses have been performed which identify phage mutants (chi) which cause recombinational hot spot activity in lambda. the hot spot activity is found in crosses of red(-) gam(-) chi(-) strains in rec(+) hosts; in the crosses reported here, both the chi(-) mutations and the hot spot are located near the right end of the chromosome. the hot spot occurs in standard crosses as well as under conditions which block dna synthesis, and is dependent on a functional host recb gene.-the chi mutation is sh ...	1974	4415485
substitution mutation in bacteriophage lambda with new specificity for late gene expression.		1974	4415976
the distribution of crossovers along unreplicated lambda bacteriophage chromosomes.	the distribution of crossovers along unreplicated chromosomes of bacteriophage lambda has been examined by determining the density distributions and genotypes of particles in the progenies of crosses of density-labeled by ordinary parents in the presence of genetic blocks to replication. the red and rec systems combined produce crossovers primarily near the ends (especially the right end) of the chromosome. removal of the generalized lambda recombination functions by red and gam mutations result ...	1974	4416166
structure of isometric viruses containing nonidentical polypeptide chains.	the theory of caspar and klug (1962) for the structure of isometric viruses has been generalized to the case in which the identical repeating unit is composed of n nonidentical polypeptide chains. this modified theory accounts for the structure of picornaviruses, the lambda phage head, cowpea mosaic virus, and phix174, while at the same time conserving the principle of having identical subunits in identical environments. furthermore, the modified theory suggests amending the triangulation number ...	1974	4418754
connection of the right-hand terminus of dna to the proximal end of the tail in bacteriophage lambda.		1974	4419247
diversity of regulation of genetic transcription. ii. specific relaxation of polarity in read-through transcription of the translocated trp operon in bacteriophage lambda trp.		1974	4427375
[verification of the mutagenicity of phage lambda dna for rat somatic cells].		1974	4432297
deletions and insertions in the immunity region of coliphage lambda: revised measurement of the promoter-startpoint distance.		1974	4432374
the effect of chloramphenicol and rifampicin on the "nicking" and "membrane attachment" of bacteriophage lambda dna.		1974	4432375
a regulator protein for the length determination of bacteriophage lambda tail.		1974	4437177
phage lambda dna packaging, in vitro.		1974	4437178
processing and assembly of the head of bacteriophage lambda.		1974	4437179
protein fusion during the assembly of phage lambda heads.		1974	4437180
extent and location of dna synthesis associated with a class of rec-mediated recombinants of bacteriophage lambda.		1974	4449124
comments on the arrangement of the morphogenetic genes of bacteriophage lambda.		1974	4453012
the rolling-circle replicative structure of a bacteriophage lambda dna.		1974	4455240
ultraviolet-induced mutation of bacteriophage lambda. induction by conjugation with ultraviolet irradiated donor cells.		1974	4457753
proceedings: maturation of phage lambda dna: dependence on replication and recombination.		1974	4461541
physical mapping of the att-n region of coliphage lambda: apparent oversaturation of coding capacity in the gam-ral segment.		1974	4466498
[formal analysis of genetic regulation circuits: control of immunity in bacteriophage lambda].		1974	4466499
locations and amounts of major structural proteins in bacteriophage lambda.		1974	4476800
letter: capsid structure of bacteriophage lambda.		1974	4141737
a spheroplast assay for recombination in bacteriophage lambda dna.		1974	4206975
mechanism of inhibition of bacillus subtilis dna polymerase 3 by the arylhydrazinopyrimidine antimicrobial agents.	arylhydrazinopyrimidines inhibit dna synthesis in bacillus subtilis by promoting formation of a specific, long-lived ternary complex with dna polymerase iii and the template-primer dna. dna polymerase iii contains an associated, single-strand-selective exonuclease which generates 5'-mononucleotides. drug inhibition of the nuclease similarly proceeds through formation of the ternary complex. the ternary complex was isolated by agarose chromatography. like inhibition of the nuclease, optimum forma ...	1974	4213240
viable molecular hybrids of bacteriophage lambda and eukaryotic dna.	a bacteriophage lambda strain has been constructed and a method developed by which dna from potentially any source can be covalently inserted through ecori cohesive ends into the middle of the lambda dna. these hybrid dnas can infect nonrestricting escherichia coli cells and can then propagate as plaque-forming phage. a unique feature of this lambda strain is that extra dna in the middle of its genome is required for plaque formation. a large number of such phages have been produced with e. coli ...	1974	4216019
an escherichia coli mutant which inhibits the injection of phage lambda dna.		1974	4132241
dna sequence analysis: a general, simple and rapid method for sequencing large oligodeoxyribonucleotide fragments by mapping.	several electrophoretic and chromatographic systems have been investigated and compared for sequence analysis of oligodeoxyribonucleotides. three systems were found to be useful for the separation of a series of sequential degradation products resulting from a labeled oligonucleotide: (i) 2-d electrophoresisdagger; (ii) 2-d pei-cellulose; and (iii) 2-d homochromatography. system (iii) proved generally most informative regardless of base composition and sequence. furthermore, only in this system ...	1974	10793670
effectiveness of oxygen in promoting x-ray-induced single-strand breaks in circular phage lambda dna and killing of radiation-sensitive mutants of escherichia coli.		1974	10876629
bacterial mutants able to partly suppress the effect of n mutations in bacteriophage lambda.	a method is described whereby bacterial mutants (sun) may be selected which are able to specifically suppress mutations in the n gene of bacteriophage lambda. the sun mutations seem to be allelic to sua mutations, which suppress the polarity of nonsense codons, since sua mutants have all of the properties of sun mutants and both are genetically linked to the ilv gene. in the light of these experiments and recent data by others, models originally suggested to explain polarity in bacterial operons ...	1975	16094982
e. coli k12 inf: a mutant deficient in prophage lambda induction and cell filamentation.	the bacterial mutant inf-3 (lambda) is not inducible and does not form filaments following thymine starvation. lysogenic induction is neither produced by ultraviolet light (uv) nor promoted by tif-1. this phenotype is due to a mutation infa3 located between 60 and 73 min on the e. coli k12 map. the inf mutant is resistant to x-ray and uv irradiation, in contrast to all other known non-inducible bacterial mutants. it is rec+ and able to perform host cell reactivation as well as uv-reactivation of ...	1975	16094997
unaltered stability of newly synthesized rna in strains of escherichia coli missing a ribonuclease specific for double-stranded rna.	pairs of very closely related escherichia coli strains were prepared, one having the wild-type allele for ribonuclease iii, an enzyme which specifically degrades double-stranded rna, and the other having a mutant rnase iii allele. growth and phage plating efficiency were compared in these strains. the rnase iii+ strains grow better than the rnase iii- strains and plate t7 and lambda phage better, but t4 plates with the same efficiency on both strains. on the other hand, the half lives of newly s ...	1975	16094999
temperate bacteriophage which causes the production of a new major outer membrane protein by escherichia coli.	under most conditions of growth, the most abundant protein in the outer membrane of most strains of escherichia coli is a protein designated as "protein 1" or "matrix protein". in e. coli b, this protein has been shown to be a single polypeptide with a molecular mass of 36,500 and it may account for more than 50% of the total outer membrane protein. e. coli k-12 contains a very similar, although probably not identical, species of protein 1. some pathogenic e. coli strains contain very little pro ...	1975	16789148
morphogenesis of the tail of bacteriophage lambda i. in vitro intratail complementation.	by studying nonsense mutants in ten of the 11 known tail genes of bacteriophage lambda we obtained the following results. concentrated tail(-)-lysates complement each other in nearly all possible (45) combinations. the efficiency of complementation is very dependent on physical parameters (lysis procedure, concentration, temperature) and on the mutants used for complementation (i.e., type of precursors present, absence or presence of abortive structures, polarity effects of some nonsense mutants ...	1975	18621349
the gamma protein specified by bacteriophage gamma. structure and inhibitory activity for the recbc enzyme of escherichia coli.	the protein encoded by the gam gene of bacteriophage lambda ("gamma protein") is a specific inhibitor of the recbc enzyme of escherichia coli. the lambda protein has been purified approximately 2,000-fold, and its structure and inhibitory activity have been characterized. it appears to be composed of two identical subunits of 16,500 daltons, inhibits all of the catalytic activities of the recbc enzyme with apparently equal efficiency, but has no effect upon any other e. coli or lambda-dnase test ...	1975	126236
inducibility of lambda phage development in escherichia coli mutants thermosensitive for dna replication.	in a thermosensitive dnaz mutant lysogenic for lambda, induction of the prophage development was provoked at the restrictive temperature. in dnad strain, spontaneous release of lambda proceeded even at 43 degrees c, but distinct induction of the prophage development was not caused by a heat treatment. similarly, shift up of growth temperature did not lead to induction of lambda in lysogens carrying thermosensitive mutation in dnah function or dna polymerase i. in dnah mutant, multiplication of l ...	1975	130012
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
regulation of phage lambda development with the growth rate of host cells: a homeostatic mechanism.		1975	166503
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
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
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 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
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
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
[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
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
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
isolation and properties of a conditionally lethal bacteriophage lambda mutated in the chi region.	a thermosensitive lambda phage mutant was isolated which can grow at high temperature only in the presence of the lambda chi gene product supplied in trans. this mutation tn was mapped within the chi region, and lambda tn phage expressed the pror-op operon only poorly at high temperature. effects of the tn mutation on expression of other operons were also examined and compared with those observed with cro27 or some tof mutations.	1975	765732
control of gene expression in bacteriophage lambda: suppression of n mutants by mutations of the antirepressor.	the lysogenization and induction properties of phages lambdasusn7ci857ai7 and lambdasusn53cro27 are described. both phages, at 32 degrees kill little, but show only a moderate frequency of lysogenization whether an amber suppressor is present or absent in the host bacterium. in the latter case, lysogens for lambdasusn7ci857ai7 or lambdasusn53ci857cro27 can exist in two different regulatory states, here called p r- and pr+. the pr+ phase is characterized by phage release and cell death at 40 deg ...	1975	765738
the role of chi mutations in the spi- phenotype of phage lambda: lack of evidence for a gene delta.	lambda red- gam- makes a small plaque on p2 lysogens (the partial spi- phenotype). it has been proposed that inactivation of an additional gene delta, mapping in the recombination region, makes the plaque bigger (the full spi- phenotype) (zissler et al., 1917b). the present paper demonstrates that the chi mutation in lambda (stahl et al., 1975) confers upon red- gam- phage the full spi- phenotype and that the deletion of the region of the chromosome attributed to delta does not. it appears unnec ...	1975	765741
isolation and properties of escherichia coli mutants which are nonpermissive for the growth of phage lambda.	by selecting survivors of lambda phage infection, mutants of escherichia coli k12 that block reproduction cycle of the phage have been isolated. fourteen of these phage-tolerant mutants (lam mutants) were chosen and characterized biochemically and genetically. it was shown that these mutants were tolerant to infection by all the lambdoid phages, except for few cases, but they were susceptible to infection by a non-lambdoid temperate phage (phi299), p1 or t phages. the mutants can be divided into ...	1975	772257
evidence for common binding sites for ferrichrome compounds and bacteriophage phi 80 in the cell envelope of escherichia coli.	mutants ton a and ton b of escherichia coli k12, known to be resistant to bacteriophage phi80, were found to be insensitive as well to albomycin, an analogue of the specific siderochrome ferrichrome. ferrichrome at micromolar concentrations strongly inhibited plaque production by phi80. preincubation with ferrichrome did not inactivate the phage. at a concentration at which ferrichrome allowed 90% inhibition of plaque formation, the chromium analogue of ferrichrome showed no detectable activity. ...	1975	803957
elements involved in site-specific recombination in bacteriophage lambda.		1975	807737
isolation of coliphage lambda ghosts able to adsorb onto bacterial cells.	we have examined three methods of lambda ghost production, starting with the [3h]leucine-labelled phage, purified by cscl density gradient sedimentation. ghosts obtained by the osmotic shock or by incubation in 5 m licl do not adsorb on bacteria. ghosts obtained by the treatment with the chelating agent edta and purified by cscl density gradient sedimentation possess well preserved adsorption properties and are virtually free of dna and infectious phage particles.	1975	809058
putrescine and certain polyamines can inhibit dna injection from bacteriophage lambda.		1975	809592
isolation, characterization and deletion mapping of amber mutations in the cll gene of phage lambda.		1975	1089335
morphogenesis of the tail of bacteriophage lambda. ii. in vitro formation and properties of phage particles with extra long tails.		1975	1089336
repressor synthesis in vivo after infection of e. coli by a prm - mutant of bacteriophage lambda.		1975	1089337
genetic and phenotypic characterization of dnac mutations.	the dna-1, dna-2, dna-7, and dna-28 mutations, all of which are located near min 89.5 on the e. coli linkage map, have been characterized further. as previously demonstrated for dna-2 and dna-28, neither the dna-1 nor dna-7 mutation affects the ability of a strain to produce bacteriophage lambda at temperatures non-permissive for the continued replication of the bacterial chromosome. the reported temperature-sensitive inhibition of lambda production in a strain carrying dna-7 is shown to be a co ...	1975	1089638
the formation of polylysogens during infection of escherichia coli with bacteriophage lambda.		1975	1090071
the role of gene nu3 in bacteriophage lambda head morphogenesis.		1975	1090075
ribonucleic acid synthesis after adsorption of the bacteriophage lambda on escherichia coli minicells.	lambda bacteriophage adsorbs on the chromosome-less small bodies (minicells) produced by aberrant cell division of escherichia coli p678-54. the plasmid-less minicells, as well as the minicells harbouring the colicinogenic factor e1, reveal a considerable inhibition of total rna synthesis after phage adsorption. both kinds of minicells synthesize rna hybridizable to lambda dna, but in the plasmid-harbouring minicells lambda rna synthesis is much more intensive.	1975	1090110
intermolecular linking and fragmentation of dna by beta-propiolactone, a monoalkylating carcinogen.	brief exposure to beta-propiolactone (bpl) increases the sedimentation rate of purified escherichia coli dna in neutral and alkaline sucrose gradients. however, when electrophoresed in polyacrylamide-agarose gels, this bpl-treated dna moves ahead of the control. longer incubation with bpl gives rise to two new fractions, the first one sedimenting as a heterogeneous material of 6-8s, and the second one of very high sedimentation velocity. in acrylamide-agarose gels, the first fraction is again re ...	1975	1090389
occurrence of the bacteriophage lambda receptor in some enterobacteriaceae.	in escherichia coli k-12, the receptor for phage lambda is an outer membrane protein which inactivates the phage in vitro. lambda receptor activity was found in extracts from all wild strains of e. coli tested, although most of them fail to support growth of the phage. in some cases this failure is due to a masking of the receptor in vivo, the bacteria being unable to adsorb the phage or to react with antireceptor antibodies. in other cases, adsorption does occur, and the nature of the block in ...	1975	1090748
proteolytic cleavage of bacteriophage lambda repressor in induction.	the bacteriophage lambda repressor, a protein that maintains the lysogenic state of a bacterium containing a lambda prophage, is cleaved when the lysogen is induced by mitomycin c or ultraviolet light. this cleavage does not occur when induction is prevented by mutational alteration either of the phage repressor or of the host reca gene product. proteolytic cleavage may be the primary mechanism of repressor inactivation in this induction pathway, or it may follow a different event which causes t ...	1975	1090931
replicating circular dna molecules in yeast.	the yeast saccharomyces cerevisiae contains a class of small circular dna molecules, approximately 2 mum in contour length (sinclair et al., 1967). in this report, it is shown that these molecules replicate as double-branched circles, similar to those observed during replication of the bacteriophage lambda and escherichia coli chromosomes. a normal rate of replication of these dna circles requires the function of a nuclear gene, cdc 8.	1975	1091361
deoxyribonucleic acid-cytosine methylation by host- and plasmid-controlled enzymes.	deoxyribonucleic acid (dna)-cytosine methylation specified by the wild-type escherichia coli k 12 mec+ gene and by the n-3 drug resistance (r) factor was studied in vivo and in vitro. phage lambda and fd were propagated in the presence of l-[methyl-3h]methionine in various host bacteria. the in vivo labeled dna was isolated from purified phage and depurinated by formic acid-diphenylamine treatment. the resulting pyrimidine oligonucleotide tracts were separated according to size and base composit ...	1975	1091619
mutations simultaneously affecting endonuclease ii and exonuclease iii in escherichia coli.	we studied mutants of e. coli originally identified as being deficient in either endonuclease ii (deoxyribonucleate oligonucleotidohydrolase, ec 3.1.4.30) or exonuclease iii [deoxyribonucleate (double-stranded) 5'-nucleotidohydrolase, ec 3.1.4.27] activity. twelve independently derived mutants were tested, including three new endonuclease ii mutants. deficiency of one enzyme was always accompanied by deficiency of the other. furthermore, temperature-sensitivity of one activity was always accompa ...	1975	1091930
insertion of a minor protein into the outer membrane of escherichia coli during inhibition of lipid synthesis.	the antibiotic cerulenin, a specific inhibitor of fatty acid synthetase systems, was used to demonstrate that a minor protein component of the outer membrane of escherichia coli, which serves as the receptor for the phage lambda, can be synthesized and inserted into the outer membrane during inhibition of lipid synthesis.	1975	1092644
electron microscope heteroduplex studies of sequence relations among bacterial plasmids: identification and mapping of the insertion sequences is1 and is2 in f and r plasmids.	heteroduplex experiments between the plasmid r6 and one strand of the deoxyribonucleic acid (dna) of a lambda phage carrying the insertion sequence is1 show that is1 occurs on r6 at the two previously mapped junctions of resistance transfer factor (rtf) dna with r-determinant dna. from previous heteroduplex experiments, it then follows that is1 occurs at the same junctions in r6-5, r100-1, and r1 plasmids. heteroduplex experiments with the dna from a lambda phage carrying the insertion sequence ...	1975	1092668
ultraviolet reactivation and ultraviolet mutagenesis of infectious lambda dna: strong inhibition by treatment of dna in vitro with uv-endonuclease from micrococcus luteus.	uv-endonuclease from microcossuc luteus induces single-stranded breaks in uv-irradiated dna of phage lambda and the average length of the fragments produced (after uv-doses to dna of 135 and 675 erg/mm2) is equal to the average spacing between pyrimidine dimers. the plaque-forming ability of uv-irradiated lambda dna used to infect ca++-treated uvr a6, uvrb5 or uvrc34 recipient escherichia coli cells (but not uve+ cells) may be significantly enhanced by treatment of lambda dna with uv-endonucleas ...	1975	1093009
a mutant of eshcerchia coli k-12, urt-43, with a temperature-sensitive defect at the incision step of the excision repair mechanism.	urt-43, which has a defect in excision repair, exhibits a temperature-dependent ultraviolet survival. it was shown that urt-43 requires protein synthesis but not dna synthesis for recovery, by examining recovery in a growth medium containing chloramphenicol or nalidixic acid. the recovery of irradiated bacteriophage lambda in urt-43 took place in a medium containing nalidixic acid at 30 degrees, but not at 41 degrees, and chloramphenicol prevented this recovery. these results seem to imply that ...	1975	1093010
the biological activity of bacteriophage dna, prepared by the cationic detergent dilution technique.	the preparation of phage lambda dna infecting e. coli k 12 with cationic detergent is described. this dna infects e. coli spheroblasts with the same efficiency as dna prepared by phenol methods.	1975	1093138
recombination-deficient deletions in bacteriophage lambda and their interaction with chi mutations.	we have isolated a new class of deletion mutants of phage lambda that extend from the prophage attachment site, att, into the gam and ciii genes. in this respect they are similar to certain of the lambda pbio transducing phage, but they differ in having a low burst size and in forming minute plaques. lytically grown stocks of the deletions contain a variable proportion of phage that produce large plaques. these have been shown to carry an additional point mutation. similar mutations, called chi, ...	1975	1093930
resolution of the dna strands of the specialized transducing bacteriophage lambda-h80c 1-857 dargf.	the dna strands of lambdoid phages with deletions or substitutions of the guanine plus cytosine-rich region in the left arm are not resolvable by complexing with poly ug followed by centrifugation in cscl. this work describes a completely general procedure for the strand resolution of these phages by hybridization with fragments of separated strands of the parent phage. in particular, resolution of the dna strands of the specialized transducing phage lambda-h80c1-857dargf is described, and evide ...	1975	1094135
mismatch repair in heteroduplex dna.	dna with base pair mismatches was prepared by annealing mixtures of genetically marked dna from bacteriophage lambda. this heteroduplex dna was used to transfect bacteria under conditions minimizing recombination. genetic analysis of the progeny phages indicates that: (i) mismatch repair occurs, usually giving rise to a dna molecule with one chain with the genotype arising from repair and one parental chain. (ii) the frequency of repair of a given mismatch to wild type depends on the marker, ran ...	1975	1094458
uptake of homologous single-stranded fragments by superhelical dna: a possible mechanism for initiation of genetic recombination.	superhelical [3-h]dna (replicative form i, rfi) of bacteriophage phix174 slowly but spontaneously took up 32-p-labeled homologous single-stranded fragments at 4 degrees. uptake was accelerated by heating to 75 degrees. rfi did not take up single-stranded fragments derived from dna of escherichia coli or from separated strands of phage lambda. uptake was inhibited by low concentrations of ethidium bromide. relaxed circular phix174 dna did not take up homologous fragments. per molecule of rfi, the ...	1975	1094467
structure of the oligomeric circular molecules of a bacteriophage lambda dna.		1975	1094676
deletion mutations of the immunity region of coliphage lambda.		1975	1094677
constitutive integrative recombination by bacteriophage lambda.		1975	1094679
recognition sequences of repressor and polymerase in the operators of bacteriophage lambda.	nucleotide sequences in two wild-type and six mutant operators in the dna of phage lambda are compared. strikingly similar 17 base pair units are found which we identify as the repressor binding sites. each operator contains multiple repressor binding sites separated by a-t rich spacers. elements of 2 fold rotational symmetry are present in each of the sites. superimposed on each operator is an e. coli rna polymerase recognition site (promoter). similarities in the sequences of the two lambda pr ...	1975	1095210
the promoters and bidirectional transcription in the immc region of p 22 and l phages.	it is proposed that the transcription of the c-2 repressor gene initiates at two promoters, pre and prm, similarly to the transcription of the c-i gene of lambda phage. in the p22 phage, these promoters are defined by mutations of c54 and k5.	1975	1095460
quantitation of the loss of the bacteriophage lambda receptor protein from the outer membrane of lipopolysaccharide-deficient strains of escherichia coli.	the recpetor for the phage lambda, a protein component of the outer membrane, is present at decreased levels in strains of escherichia coli that are deficient in lipopolysaccharide. loss of the protein was quantitated both by an assay of the phage receptor function and by an assay of antiserum-blocking ability to detect inactive protein. the loss of protein was correlated with the loss of sugar residues and phosphage from the core region of the lipopolysaccharide. implications for the importance ...	1975	1095562
termination of transcription in bacteriophage lambda. heterogeneous, 3'-terminal oligo-adenylate additions and the effects of rho factor.	rna transcripts were synthesized in vitro from a lambda dna template with purified escherichia coli rna polymerase either in the presence or absence of the protein termination factor, rho. the products were initially characterized by electrophoresis on polyacrylamide slab gels, and two of the lower molecular weight discrete species (6 s and 4 s rna) were further characterized by standard two-dimensional "fingerprint" analysis. production of the 4 s rna was strongly affected by the presence of rh ...	1975	1095576
chloramphenicol stimulation of lysogeny by lambda regulatory mutants.	inhibition of protein synthesis in escherichia coli by amino acid starvation or chloramphenicol addition increases the frequency of lysogeny by lambda phage two- to fourfold. lambda ciii mutants, which normally lysogenize at very low frequencies, lysogenize at very high frequencies in the presence of chloramphenicol.	1975	1095779
inhibitory effect of u.v. -irradiation on the formation of twisted circular lambda dna.	ultra-violet irradiation of lambda phage results in an inhibition of conversion of lambda dna in host cells from the initial linear form to twisted circular form. the formation of open circular lambda dna in vitro (formation of hershey's circle) was quite resistant to the irradiation. the occurrence of denaturation of ultraviolet irradiation was detected in lambda dna.	1975	1079515
[competence in escherichia coli cells. iii. formation of competent states in escherichia coli x7026 and escherichia coli hfr h cells during storage in different conditions].	the competence formation in 2 strains of escherichia coli x7026 and hfr h to isolated phage gamma dna after the prolonged treatment of cells with ca++ ions at low temperatures was investigated. in both strains studied the sensitivity of cells to phage lambda dna increased during several days of maintenance at 4 degrees c in 0.2 m cacl2, and reached the maximal value in 24-48 hours for e. coli hfr h cells, and in 72-96 hours for e. coli x7026 cells. cells maintained in cacl2 for 24 hours and more ...	1975	767199
integrative recombination of bacteriophage lambda dna in vitro.	an in vitro system for the production of integrative recombinant dna of bacteriophage lambda is described. the in vitro recombination mimics the in vivo integration of viral dna into host dna in its requirement for int gene product, for the presence of a thermolabile component, and for the limitation of the recombination to a pair of specialized sites (attachment sites) on the dna. the enzymes are extracted from escherichia coli containing phage lambda gene products. the substrate is the dna fro ...	1975	1055366
transcription termination and late control in phage lambda.	a transcription termination site occurs between the promoter for late gene expression of bacteriophage lambda and the late genes themselves. it is proposed that the lambda q gene product controls late gene expression by over-coming this termination barrier.	1975	1059112
transposition of r factor genes to bacteriophage lambda.	transpositions of segments of r factor (antibiotic resistance plasmids) to bacteriophage lambda have been selected and characterized. cells of escherichia coli harboring r factors that determine kanamycin resistance were infected with phage lambda, and lambdakan transducing lines were obtained. each of the three examined is unusual when compared to lambda transducing phages containing e. coli chromosomal genes: the kan insertions (a) occur at several sites, each well removed from the integration ...	1975	1059152
acquisition of a determinant for chloramphenicol resistance by coliphage lambda.	a determinanat for chloramphenicol resistance, cam, initially detected on a resistance transfer factor (rtf) and since transferred to phage p1, may be acquired from p1 by coliphage lambda. lambdapcam are obtained when a lambda prophage is induced in bacteria which also harbor p1 cam prophage. lambdacam formation is not dependent upon host rec or lambda red recombination functions. electron microscopic heteroduplex analysis shows that the cam locus in two lambdapcams is a 5% addition of dna in th ...	1975	1061090
repression and autogenous stimulation in vitro by bacteriophage lambda repressor.	purified lambda repressor protein is shown to reduce the lambda dna-directed synthesis of proteins in vitro as determined both by net amino-acid incorporation and by analysis of specific lambda-coded proteins resolved by sodium dodecyl sulfate/polyacrylamide slab gel electrophoresis. by means of different lambda dna templates carrying deletion and point mutations in the operators o-l or o-r, it has been possible to demonstrate repression of the synthesis of two classes of lambda proteins. the sy ...	1975	1055378