Publications

the nature and origin of a class of essential gene substitutions in bacteriophage lambda.		1975	1099781
electron microscopic study of the repressor of bacteriophage lambda and its interaction with operator dna.		1975	1099211
isolation of specialized transducing bacteriophage lambda carrying genes of the l-arabinose operon of escherichia coli b/r.	a heat-inducible lysis-defective phage lambda (lambdaci857s7) has been integrated at multiple sites within the l-arabinose region (aracoibad) of a strain of escherichia coli k-12 deleted for the normal lambda attachment site (lambdaattdelta). the lambda phage has become integrated with opposite orientations at two different loci within the aratb gene and with the "normal" orientation (clockwise n-ra-j) at a single site in the arac gene. the burst size, spontaneous-curing frequencies, and number ...	1975	1099071
regulation of early protein synthesis in bacteriophage lambda.		1975	1098280
host mutants resistant to phage lambda killing.		1975	1098279
the kil gene of bacteriophage lambda.		1975	1098278
strand breakage of coliphage lambda dna supercoils in infected lysogens. i. genetic and biochemical evidence for two types of nicking processes.		1975	1098274
proposed mechanism of bacteriophage lambda induction: acquisition of binding sites for lambda repressor by dna of the host.	interference with the in vitro binding of lambda phage repressor to lambda operator dna was observed when escherichia coli dna containing the following lesions was present in the reaction mixture: (a) dna with single-strand breaks from pancreatic dnase (nicked dna); (b) dna isolated from thymine-straved cells; (c) dna from ultraviolet-treated cells; (d) dna of mitomycin-treated cells; and (e) dna from a temperature-sensitive ligase mutant after 1 hr at 42 degrees. normal e. coli dna did not inte ...	1975	1098048
determination of genes, restriction sites, and dna sequences surrounding the 6s rna template of bacteriophage lambda.	a major product of the transcription of bacteriophage lambda dna in vitro is the 6s rna. this article presents a detailed mapping of restriction endonuclease cleavage sites about the region of the 6s rna template within the lambda genome. restriction fragments defined by these sites have been used to localize the 6s rna template within the physical and genetic maps of the lambda genome. nucleotide sequence analysis of one of these fragments has largely confimed the nucleotide sequence of the 6s ...	1975	1098044
packaging of prophage and host dna by coliphage lambda.		1975	1097937
on the mechanism of production of tandem genetic duplications in phage lambda.		1975	1097713
bacteriophage lambda head morphogenesis: studies on the role of dna.		1975	1097706
genetic and physical studies of lambda transducing bacteriophage carrying the beta subunit gene of the escherichia coli ribonucleic acid polymerase.	the prophage lambdac1857 was inserted into the bfe gene located near rif (the structural gene for the beta subunit of deoxyribonucleic acid [dna]-dependent ribonucleic acid polymerase) on the escherichia coli chromosome. induced lysates (low-frequency transducing lysates) of such a lysogen contained defective lambda phage particles (lambdadrif+) that can specifically transduce the wild-type rif+ gene. upon transduction into a recipient strain carrying reca, heterogenotes harboring both the wild- ...	1975	1097397
physiological transition of a coliphage lambda dna replication.	the "rolling-circle" replicative intermediate (sigma-type molecules) which is normally produced in the late stage of coliphage lambda dna replication can be found during the first round of lambda dna replication if cells infected with lambda replication mutant ots28 are incubated at the nonpermissive temperature until the late stage of the latent period of lambda infection. after shifting to the permissive temperature, the vast majority of replicating forms are sigma-type rolling circle even dur ...	1975	1096948
induction and mutagenesis of prophage lambda in escherichia coli k12 by metabolites of aflatoxin b1.	like most carcinogens, aflatoxin b1 must be activated by mammalian microsomal enzymes to give rise to coupounds active on bacteria. these compounds act as inducers of e. coli k12 (lambda) at a high efficiency, whereas unmodified aflatoxin b1 has no effect. moreover, metabolites of aflatoxin b1 have a mutagenic action on phage lambda, as shown by the appearance of clear plaque mutants. we propose the hypothesis that the same derivative is responsible for carcinogenesis of liver cells by aflatoxin ...	1975	1095913
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
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
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
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
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
constitutive integrative recombination by bacteriophage lambda.		1975	1094679
deletion mutations of the immunity region of coliphage lambda.		1975	1094677
structure of the oligomeric circular molecules of a bacteriophage lambda dna.		1975	1094676
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
the role of gene nu3 in bacteriophage lambda head morphogenesis.		1975	1090075
the formation of polylysogens during infection of escherichia coli with bacteriophage lambda.		1975	1090071
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
repressor synthesis in vivo after infection of e. coli by a prm - mutant of bacteriophage lambda.		1975	1089337
morphogenesis of the tail of bacteriophage lambda. ii. in vitro formation and properties of phage particles with extra long tails.		1975	1089336
isolation, characterization and deletion mapping of amber mutations in the cll gene of phage lambda.		1975	1089335
the use of antibiotics actinomycin d and distamycin a for mapping of phage lambda hindiii fragments.		1976	1086799
location in bacteriophage lamdba dna of cleavage sites of the site-specific endonuclease from bacillus amyloliquefaciens h.	the sites in escherichia coli bacteriophage lambda dna cleaved by the site-specific endonuclease isolated from bacillus amyloliquefaciens h (bami) are found to be at 0.114, 0.466, 0.580, 0.713, and 0.861 lambda units. the sites were located by analysis of the products of digestion of lambda dna and lambda-ara transducing phage dna, and verified by double digestion with bami and ecori.	1976	1083914
mechanisms of protection of gamma-irradiated bacteriophage lambda by proflavine.	the protective effect of proflavine on gamma-irradiated bacteriophage lambda and its isolated dna was investigated under conditions of predominantly indirect or direct effects. in both conditions addition of small amounts of the dye during irradiation of phage or dna was shown to enhance their biological activity. protection against indirect effects results probably from extensive scavenging of radioinduced water radicals within the medium. on the other hand the results obtained at minus 196 deg ...	1975	1080138
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
[new mutagens of bacteriophage lambda affected during lysogeny regulation].		1976	1071226
[genetic and functional characterization of mutants of the lambda phage affected in the regulation of lysogenization].		1976	1070772
single burst study of rec- and red-mediated recombination in bacteriophage lambda.	single bursts from three-point crosses of bacteriophage lambda were analyzed for recombination of markers several thousand nucleotide pairs apart. single recombination, mediated by the rec system of escherichia coli, is usually reciprocal. double recombinants are also significantly correlated in single bursts, although the correlation is weaker than for reciprocal singles. reciprocity is not found in crosses mediated by the lambda red system. with respect to certain other paraments of recombinat ...	1976	1070013
construction of plasmids carrying the ci gene of bacteriophage lambda.	by techniques of recombination in vitro, we have constructed a plasmid bearing the repressor gene (ci) of bacteriophage lambda fused to the promoter of the lac operon. strains carrying this plasmid overproduce lambda repressor. this functional ci gene was reconstituted by joining dna fragments bearing different parts of that gene. flush end fusion techniques, involving no sequence overlap, were necessary for the construction; in certain cases, the abutting of the dna molecules bearing ends gener ...	1976	1069307
colicin e2 is dna endonuclease.	colicin e2 purified by conventional methods contains a tightly bound low-molecular-weight protein, as has been found with purified colicin e3 [jakes,n.&zinder,n.d.(1974) proc. natl. acad. sci. usa 71, 3380-3384]. such e2 preparations do not cause dna cleavage in vitro. after separation from the low-molecular-weight protein, colicin e2 retained the original in vivo killing activity, and in addition showed a high activity in vitro in cleaving various dna molecules, such as a cole1 hybrid plasmid a ...	1976	1069283
integration of eukaryotic genes for 5s rna and histone proteins into a phage lambda receptor.	highly purified hindiii restriction fragments of xenopus laevis 5s dna and of psammechinus miliaris histone dna have been covalently inserted into a derivative of phage lambda. this phage, genetically constructed by murray et al. (1), contains only a single target for hindiii in the ci gene. viable hybrid molecules were detected as clear plaque-forming phage after transfection of e. coli, the vast majority of which were shown by hybridization to be recombinants of the desired type. the lambdasam ...	1976	1069257
construction of a hybrid col e1 plasmid carrying the gene for bacteriophage lambda repressor.	a biologically active hybrid dna molecule was constructed from plasmid col e1 and the eco r1 fragment of lambda dna containing the gene for lambda repressor. the presence of this gene in the hybrid molecule was demonstrated genetically. the hybrid plasmid contains two closely located targets for restriction endonuclease hind 111 in the integrated fragment. thus, the plasmid may be used as a vector not only for eco r1 fragments but also for hind 111 fragments.	1976	1069256
restriction assay for integrative recombination of bacteriophage lambda dna in vitro: requirement for closed circular dna substrate.	a novel assay has been developed for in vitro genetic recombination of dna. substrate and product dnas are cleaved with a restriction endonuclease and the resulting fragments are separated by electrophoresis in agarose gels. the substrate dna has been chosen so that the recombination to be studied deletes a segment of dna. the remaining dna gives rise to a unique restriciton fragment, as does the dna segment that has been removed. the method provides a convenient and physical, rather than geneti ...	1976	1068464
methods for identification of recombinants of phage lambda.	two methods are described which allow the screening of a large number of phage plaques for a specific dna sequence carried by the phage or a specific antigen produced within the phage plaque. these methods were set up with lambda and lambdalac phages. phage plaques were transferred onto nitrocellulose filters by desiccation in 0.1 m naoh, and the lac sequence was detected by hybridization to radioactive lac mrna. beta-galactosidase was detected by reaction with anti-beta-galactosidase immune ser ...	1976	1068453
improved derivative of a phage lambda ek2 vector for cloning recombinant dna.		1976	1067476
purification and properties of a dna-binding protein with characteristics expected for the cro protein of bacteriophage lambda, a repressor essential for lytic growth.	the cro protein specified by bacteriophage lambda is a repressor essential for normal lytic growth of the virus, thus having a physiological role distinct from that of ci, the repressor that maintains lysogeny. we have purified a lambda-specific dna-binding protein with the requirements for synthesis and biochemical activities expected for cro protein from studies in vivo. as isolated, the protein appears to be a dimer of molecular weight approximately 18,000 with dna-binding properties that are ...	1976	1065873
determination of nucleotide sequences beyond the sites of transcriptional termination.	a procedure is described by which a discrete high-molecular-weight rna transcription product can be used as a primer by dna polymerase (dna nucleotidyltransferase; ec 2.7.7.7; deoxynucleoside triphosphate: dna deoxynucleotidyltransferase) for determining nucleic acid sequence in the template dna beyond the 3'-terminus of the transcript. this procedure is applied to two lambda phage transcripts, the 4s "oop" rna [short l-strand rna transcript from the region of origin of replication (ori) and the ...	1976	1062781
deletions of lambda phage locating a prm mutation within the rightward operator.	two deletion-substitution mutations of phage lambda, spi-113 and spi-274, are shown to remove about half of the rightward operator or. physiological studies show that spi-113 is still repressible. thus, the 50 or so nucleotides of or deleted in this mutant are not absolutely essential for repression. prm-116, which inactivates the promoter essential for the maintenance of lambda repressor synthesis, is located within or between the endpoints of spi-113 and spi-274.	1976	1062780
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
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
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
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
nucleotide sequence of the rightward operator of phage lambda.	the sequence of 72 base pairs of the rightward operator (o-r) of bacteriophage lambda is presented as determined with simple and rapid methods for direct dna sequencing. the sequence of an operator mutant is also described. the methods are of general use in sequencing dna fragments with unique 5' ends up to 50 base pairs in length. previous experiments have shown that this operator contains multiple sites recognized by the lambda phage repressor. we believe we have identified three of these site ...	1975	1055375
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
isolation of the bacteriophage lambda a-gene protein.	an in vitro assay for measuring the activity of the phage lambda a-gene product has been developed. the assay is based on the observation that a-donor extracts complement a minus extracts for packaging of exogenous immature lambda dna into phage particles. a partial purification of the a-gene product activity using this assay is presented. a method is suggested by which this a protein-dependent in vitro system might be manipulated to analyze the mechanism of reforming the lambda cohesive termini ...	1975	1054839
the site-specific deoxyribonuclease from bacillus pumilus (endonuclease r.bpu1387).	a new site-specific endonuclease (dnase) was isolated from the cells of bacillus pumilus ahu 1387 strain. this enzyme (endonuclease r.bpu 1387) introduced double-stranded scissions at unique sites on dna's of coli phage lambda, lambdadvl, coli phage t7, bacillus phage phi105c, bacillus phage sp10, and simian virus 40, in the presence of magnesium ion. the activity was stimulated by the presence of nacl.	1976	1018024
isolation of suppressor sensitive mutants in the ai gene of phage lambda.	previous experiments have shown that mutations in the ai gene can suppress the growth defect of lambda n- phages. many temperature resistant derivatives of phage lambdatsn9 have been isolated and among these 5 have been found which are ai- and have an amber suppressible behaviour. these mutants can help in defining the role of the ai gene in phage lambda development.	1976	1012269
analysis of a temperature sensitive mutation in gene cii of bacteriophage lambda.	the mutation ciits612 was found to map outside the immunity region of phage lambdaimm21 hybrid. as expected of a cii mutation, lambdaciits612 is unable to stimulate either ci repressor or int synthesis during the establishment of lysogeny. these results indicate that part of the cii gene of lambda is homologous to that of lambdaimm21 phage.	1976	1012266
[new lambdoid phages of escherichia coli. ii. comparison of several genetic characteristics with lambda phages].	functions of some newly isolated lambdoid phages and phage lambda genes were compared by their ability to interact with unrelated phages and the product of the bacterial gene gro p. 19 of 23 lambdoid phages studied interfere with prophage p2, that points out the presence of functionally active genes, essential for spi+ phenotype in their genomes. the development of 4 lambdoid phages with spi- phenotype is independent on the prophage p2 presence. most of lambdoid phages show the reduced growth ab ...	1976	1010327
[new lambdoid escherichia coli phages. i. isolation, group immunity and recombination with lambda phage].	550 bacterial strains were isolated from sewage. 69 of them were lysogenic by phages active on escherichia coli. the phages were divided into two groups on the basis of uv-inducibility, the ability to form plaques on rep-e. coli mutants and particle morphology: lambdoid (23 phages) and related to p2 (46 phages). hybrid phages isolated from the crosses of lambdoid phages with phage lambda harboured the region imm lambda and the gene of adsorption specificity from other parent. ten groups of heter ...	1976	1010326
a complex control circuit. regulation of immunity in temperate bacteriophages.	temperate bacteriophages can display in a stable way two essentially different behaviours. in the immune state, a gene (ci) produces a repressor which prevents expression of all the other viral genes; in the non-immune state the typically viral functions are expressed. the choice between the two pathways and the establishment of one of them have much in common with cell determination and differentiation. this choice depends on a complex control system, in fact one of the most intricate nets of r ...	1976	1009948
the use of terminal blocking groups for the specific joining of oligonucleotides in rna ligase reactions containing equimolar concentrations of acceptor and donor molecules.	under the conditions that rna ligase converts the tetranucleotide, pa-a2-a, to larger polynucleotides, no such polymerization can be detected with the derivative, pa-a2-a(meoet), that possesses a terminal 2'-0-(alpha-methoxyethyl) group. the protection against self condensation offered by the methoxyethyl group in this system allows the specific joining of donor and acceptor oligonucleotides in reaction mixtures containing equimolar concentrations of the two species. thus, the enzyme, together w ...	1976	1005114
heat-sensitive dna-binding activity of the ci product of bacteriophage lambda.	the binding of lambda gene ci product to lambda dna was studied at temperatures from 0 degrees c to 46 degrees c. binding activity of the products of cits mutants was higher at 22 degrees c than at 0 degrees c, 26 degrees c or 30 degrees c. both ci+ and cits products lost dna-binding activity at 46 degrees c, but after subsequent cooling to 22 degrees c, they regained 50-100% of their activity.	1976	1004487
morphogenesis of bacteriophage lambda tail. polymorphism in the assembly of the major tail protein.		1976	1003470
[substrate of a uv-induced repair system providing for w-reactivation of lambda phage].	escherichia coli uvra, pola and uvrd cells carrying non-uv-inducible prophage lambdac1857ind- were infected with 3h-thymidine labelled homoimmune phage lambdac1857, and the effect of uv-irradiation of super-infecting phage and lysogenic bacterial cells on the content of intracellular covalently-closed lambda dna circles (cccdna) and pyrimidine dimer content in lambda dna are studied. uv-irradiation of host cells results in two-fold increase of relative content of cccdna of uv-irradiated phage la ...	1976	1001892
substrate specificity of the ultraviolet-endonuclease from micrococcus luteus. endonucleolytic cleavage of depurinated dna.	the ultraviolet-endonuclease isolated from micrococcul luteus, specific for pyrimidine dimers, is able to attack not only ultraviolet-irradiated dna (leading to 3'oh-5'po4 single-strand breaks) but also superhelical covalently-closed circular dna of phage lambda damaged by heating at 70 degrees c, ph 5.93. the number of endonuclease-sensitive defects in the dna corresponds to the number of alkalilabile bonds (apurinic sites) induced by heating. competition between ultraviolet-induced lesions and ...	1976	991858
inhibition of bacteriophage lambda, t1, and t7 development by r plasmids of the h incompatibility group.	r plasmids from chloramphenicol-resistant salmonella from ontario are shown to belong to the h(2) incompatibility subgroup and to mediate a broad-spectrum, phage inhibition function.	1976	984810
nucleotide clusters in deoxyribonucleic acids. xiv. pyrimidine oligonucleotides of the left and right halves and lambdadv region of bacteriophage lambda dna.		1976	982832
formation of covalently closed cyclic dimers and catenanes of escherichia coli phage lambda in the absence of known recombination systems.		1976	982813
[mapping of phage lambda dna using the antibiotic distamycin].		1976	971663
protection of particular cleavage sites of restriction endonucleases by distamycin a and actinomycin d.	it is shown here that distamycin a and actinomycin d can protect the recognition sites of endo r.ecori, ecorii, hindii, hindiii, hpai and hpaii from the attack of these restriction endonucleases. at proper distamycin concentrations only two endo r.ecori sites of phage lambda dna are available for the restriction enzyme--sri1 and sri4. this phenomenon results in the appearance of larger dna fragments comprising several consecutive fragments of endo r.ecori complete cleavage. the distamycin fragme ...	1976	967694
the capsid protein of bacteriophage lambda and of its prehead.		1976	966283
interaction of host and viral regulatory mechanisms: effect of the ion cell division defect on regulation of repression by bacteriophage lambda.		1976	966281
synthesis of morphogenetic proteins by mutants of bacteriophage lambda carrying tandem genetic duplications.		1976	960570
autoregulation and function of a repressor in bacteriophage lambda.		1976	959843
genetic exchanges caused by ultraviolet photoproducts in phage lambda dna molecules: the role of dna replication.	genetic recombination induced by structural damage in dna molecules was investigated in e. coli k12 (lambda) lysogens infected with genetically marked phage lambda. photoproducts were induced in the phage dna before infection by exposing them either to 313 nm light in the presence of acetophenone or to 254 nm light. to test the role of the replication of the damaged phage dna on the frequency of the induced recombination, both heteroimmune and homimmune crosses were performed. first, samples of ...	1976	958200
a reinvestigation of 5' leads to 3' polarity in 40s ribosomal rna precursor of xenopus laevis.	the 5' leads to 3' polarity of the 40s precursor rrna molecule relative to the location of the 18s and 28s rna regions in the precursor has been reinvestigated. fragments of rdna derived by the restriction endonuclease ecori and cloned in e. coli were partially digested with the exonuclease induced by bacteriophage lambda and with exonuclease iii from e. coli. the resulting rdna fragments with single-stranded tails were hybridized separately with 18s and 28s rrna, and the formation of the hybri ...	1976	954098
[study of the virustatic action of rimantadine based on a phage-bacterium model].	the action of rimantadin on the lambda phages was studied. the maximal inhibitory effect on the compound was observed on the 1st-6th minutes after the infection. there was no such effect on the t-4 and lambda phage replication. according to the data of incorporation of the radioactive precursors into the phage dna, rna, and proteins, and the manifestation of the rimantadin action on phage replication it was supposed that the inhibitory effect of rimantadin was determined by its influence on th ...	1976	947381
4s oop rna is a leader sequence for the immunity-establishment transcription in coliphage lambda.	oop rna, which is initiated at the po promoter and is 81 nucleotides long, can function as a leader sequence for the lambda immunity establishment transcription, previously believed to originate at a special promoter pre located in the y region. thus, oop rna seems to have a dual role, either favouring the lytic cycle as a primer for the initiation of lambda dna replication, or leading to the establishment of lysogeny when elongated into the imm transcript, which directs synthesis of the repress ...	1976	934330
internal inversion used to study regulation of the int gene in bacteriophage lambda.		1976	934307
deletion mutations and the replication of dna in bacteriophage lambda.		1977	929978
physical structure of the replication origin of bacteriophage lambda.	the nucleotide sequence of part of the replication region of wild-type bacteriophage lambda and of four mutants defective in the origin of dna replication (ori-) has been determined. three of the ori- mutations are small deletions, and one is a transversion. the sequence of the origin region, defined by these mutations, contains a number of unusual features.	1977	929187
genetic structure of the replication origin of bacteriophage lambda.	a fragment of bacteriophage lambda dna produced by the restriction endonuclease eco ri and extending from the immunity region to a point inside gene o is found to have a fully functional origin of replication. seven ori- mutations of lambda cluster in a small region just to the left of the eco ri cleavage site which defines the right end of this fragment. these mutations lie within gene o.	1977	929186
construction of chimeric phages and plasmids containing the origin of replication of bacteriophage lambda.	segments of the replication control region of bacteriophage lambda (lambda) and lambda mutants defective in replication were attached in vitro to the phi80 phage vector charon 3 and to the plasmid vector mini col el (pvh51). the chimeric phages and plasmids have been used to localize the origin of lambda dna replication and to facilitate a structural analysis of the lambda replicator.	1977	929185
mapping of restriction sites in the attachment site region of bacteriophage lambda.	a find structure map of the ecori fragment containing the lambda attachment-site region has been constructed. 38 different restriction endonucleases have been employed and 170 sites located in this fragment. in addition, sites in adjacent regions have been determined for several enzymes. complete cleavage maps of the entire lambda genome have been obtained for endonucleases bglii, blui, kpni, saci, sacii, sali and xbai. the strategy employed for mapping included comparison of deletion and substi ...	1977	927438
rapid method for the purification of bacteriophage lambda by gel filtration.		1977	924534