Publications

inactivation of bacteriophage lambda, escherichia coli, and candida albicans by ozone.	the effects of ozone (o3) on three types of microbes were studied. test suspensions were exposed to 600 ppm o3 at room temperature. control experiments were performed under identical conditions using oxygen gas. bacteriophage lambda was completely inactivated at 10 min while escherichia coli and candida albicans were only inactivated by factors of 10(5) and 10(4) respectively at 40 min. exposure of a mixed microbial suspension to o3 for 5 min resulted in 100% killing of bacteriophages while the ...	1998	9684309
stochastic kinetic analysis of developmental pathway bifurcation in phage lambda-infected escherichia coli cells.	fluctuations in rates of gene expression can produce highly erratic time patterns of protein production in individual cells and wide diversity in instantaneous protein concentrations across cell populations. when two independently produced regulatory proteins acting at low cellular concentrations competitively control a switch point in a pathway, stochastic variations in their concentrations can produce probabilistic pathway selection, so that an initially homogeneous cell population partitions ...	1998	9691025
rut sites in the nascent transcript mediate rho-dependent transcription termination in vivo.	the in vitro function of the coliphage lambda tr1 rho-dependent terminator is governed primarily by a tripartite upstream sequence element designated rut. to determine the contribution of the different components of the rut site to terminator function in the normal context of coupled translation of the nascent cro message, tr1 variants lacking different rut site sequences were tested for terminator function in vivo. intact ruta and rutb sequences were both necessary for efficient termination. ho ...	1998	9694820
oligohistidine tag mutagenesis of the lambda holin gene.	holins are a diverse group of small integral membrane proteins elaborated by bacteriophages to lyse bacterial hosts and effect release of progeny phages in a precisely timed manner. recently, the holin s gene of phage lambda was overexpressed and the holin protein was purified to homogeneity by means of an oligohistidine tag procedure and immobilized metal affinity chromatography (d. l. smith, d. k. struck, j. m. scholtz, and r. young, j. bacteriol. 180:2531-2540, 1998). numerous locations withi ...	1998	9696770
biochemical and genetic analysis of lambdaw, the newly isolated lambdoid phage.	otherwise isogenic escherichia coli cp78 (rela+) and cp79 (rela-) strains are commonly used in studies on the stringent control, the bacterial response to amino acid starvation. we found that these strains are lysogenic for a phage which is spontaneously induced with a low frequency, producing virions able to infect other e. coli strains. genetic studies, restriction analysis of the phage dna genome, and electron microscopy revealed that this phage is very similar to, but not identical with, bac ...	1998	9701518
cloning of the groe operon of the marine bacterium vibrio harveyi using a lambda vector.	groes and groel genes encode two co-operating proteins groes and groel, belonging to a class of chaperone proteins highly conserved during evolution. the groe chaperones are indispensable for the growth of bacteriophage lambda in escherichia coli cells. in order to clone the groel and groes genes of the marine bacterium vibrio harveyi, we constructed the v. harveyi genomic library in the lambdaembl1 vector, and selected clones which were able to complement mutations in both groe genes of e. coli ...	1998	9701519
the escherichia coli rna polymerase alpha subunit and transcriptional activation by bacteriophage lambda cii protein.	bacteriophage lambda is not able to lysogenise the escherichia coli rpoa341 mutant. this mutation causes a single amino acid substitution lys271glu in the c-terminal domain of the rna polymerase alpha subunit (alphactd). our previous studies indicated that the impaired lysogenisation of the rpoa341 host is due to a defect in transcriptional activation by the phage cii protein and suggested a role for alphactd in this process. here we used a series of truncation and point mutants in the rpoa gene ...	1998	9701520
study of the relatedness of isolates of shigella flexneri and shigella sonnei obtained in 1986 and 1987 and in 1994 and 1995 from hong kong.	we used pulsed-field gel electrophoresis (pfge) to study the genetic relatedness of 235 isolates of shigella flexneri and shigella sonnei collected in hong kong (97 isolates from 1986 and 1987 and 138 isolates from 1994 and 1995). altogether, 13 gels were run with bacteriophage lambda ladder dna (pharmacia) as an external reference in every sixth lane, standardized reagents and methods, and isolates randomized for species and years. for quantitative illustration of the relationships within a lar ...	1998	9705363
atp-reactive sites in the bacteriophage lambda packaging protein terminase lie in the n-termini of its subunits, gpa and gpnu1.	atp-reactive sites in terminase and its subunits have been successfully identified using three different affinity analogs of atp (2-and 8-azidoatp and fitc) gpa, the larger subunit of terminase, was shown to have a higher affinity for these analogs than gpnu1, the smaller subunit. the suitability of these reagents as affinity analogs of atp was demonstrated by atp protection experiments and in vitro assays done with the modified proteins. these analogs were thus shown to modify the atp-reactive ...	1998	9705918
in vivo activities of groel minichaperones.	fragments encompassing the apical domain of groel, called minichaperones, facilitate the refolding of several proteins in vitro without requiring groes, atp, or the cage-like structure of multimeric groel. we have identified the smallest minichaperone that is active in vitro in chaperoning the refolding of rhodanese and cyclophilin a: groel(193-335). this finding raises the question of whether the minichaperones are active under more stringent conditions in vivo. the smallest minichaperones comp ...	1998	9707566
rapid degradation of polyadenylated oop rna.	the oop rna is a short (77 nucleotides (nt)) transcript encoded by bacteriophage lambda which acts as an antisense rna for lambda cii gene expression. recently we demonstrated that oop rna is specifically polyadenylated at its 3' end by poly(a) polymerase i (pap i), the pcnb gene product. here we demonstrate that the half life of oop rna is 3 times longer in the pcnb mutant relative to the pcnb+ host, indicating that polyadenylation of this transcript causes its accelerated degradation. although ...	1998	9710253
defining the structural and functional roles of the carboxyl region of the bacteriophage lambda excisionase (xis) protein.	the bacteriophage lambda excisionase (xis) protein is required for excisive site-specific recombination. xis is composed of 72 amino acids and binds cooperatively to two dna sites (x1 and x2) that are arranged as direct repeats. alternatively, xis binds cooperatively with the host-encoded factor for inversion stimulation (fis) protein at the x1 and f sites, respectively. here we analyzed the effects of missense substitutions from codon 57 to the carboxyl end of the protein and nonsense mutations ...	1998	9710537
roles of the periplasmic domain of escherichia coli ftsh (hflb) in protein interactions and activity modulation.	ftsh is a membrane-bound and atp-dependent protease of escherichia coli, known to degrade secy, a membrane protein for protein translocation, and cii, a soluble transcription factor for lysis/lysogeny decision of phage lambda. ftsh forms a homo-oligomeric complex as well as a hetero-oligomeric complex with hflkc, a putative modulator of ftsh. although ftsh has a small periplasmic region, hflkc is mostly exposed to the periplasmic space. we studied the roles of the periplasmic region of ftsh by e ...	1998	9712851
the ihf mrna levels decline as neisseria gonorrhoeae enters the stationary growth phase.	integration host factor (ihf) is a small heterodimeric dna binding protein found in all gram-negative bacteria and is implicated as a transcription cofactor of pile in neisseria gonorrhoeae (hill, s.a., samuels, d.s., carlson, j.h., wilson, j., hogan, d., lubke, l., belland, r.j., 1997. integration host factor is a transcriptional cofactor of pile in neisseria gonorrhoeae. mol. microbiol. 23, 649-656). the ihf genes (ihfa and ihfb) were cloned from n. gonorrhoeae through functional complementati ...	1998	9714829
excess production of phage lambda delayed early proteins under conditions supporting high escherichia coli growth rates.	bacteriophage lambda is unable to lysogenize escherichia coli hosts harbouring the rpoa341 mutation due to a drastic reduction in transcription from cii-activated lysogenic promoters (pe, pi and paq). in addition, the level of early transcripts involved in the lytic pathway of lambda development is also decreased in this genetic background due to impaired n-dependent antitermination. here, it is demonstrated that despite the reduced level of early lytic pl- and pr-derived transcripts, lytic grow ...	1998	9720043
characterization of the closed complex intermediate formed during transcription initiation by escherichia coli rna polymerase.	we have carried out detailed dnase i footprinting studies of the closed complex formed on the phage lambda prmup-1 delta265 promoter under reaction conditions such that the contribution of the open complex to the footprint was negligible. detailed quantification shows that the closed complex detected has the same binding constant as that determined in kinetic studies. the footprinting pattern of the closed complex shows major differences from that of the open complex. not only is it about 20 bas ...	1998	9722594
stimulation of open complex formation by nicks and apurinic sites suggests a role for nucleation of dna melting in escherichia coli promoter function.	we report the effects of depurination and prenicking at various positions of the phage lambda prmup-1delta265 promoter dna on the rate of open complex formation. we have found that depurination and prenicking at positions around the -10 region strongly stimulated the rate of open complex formation. since nicking and depurination are known to destabilize dna helical structure, our observations indicate that the instability of the -10 region is important for open complex formation. we further infe ...	1998	9722595
genomic features of human pkr: alternative splicing and a polymorphic cgg repeat in the 5'-untranslated region.	the double-stranded rna-dependent protein kinase (pkr) is a serine/threonine kinase that plays an important role in the antiviral activities of interferon (ifn). to determine the organization and regulation of the pkr locus, lambda phage and bacterial artificial chromosome (bac) clones containing the human pkr gene were isolated. characterization of these clones revealed that pkr has 17 exons and 16 introns dispersed in a genomic region of 50 kb. sequence analysis of the pkr 5'-flanking region i ...	1998	9726442
analysis of higher order intermediates and synapsis in the bent-l pathway of bacteriophage lambda site-specific recombination.	the integrase protein of bacteriophage lambda mediates recombination via four distinct pathways. the recent in vitro reconstitution of the efficient bidirectional reaction between two attltenp'1 target sites now allows comparisons of this pathway, known as the bent-l pathway, with the inefficient bidirectional straight-l pathway and with the efficient but unidirectional pathways of integration and excision. to this end, a series of higher order intermediates of the bent-l pathway was characteriz ...	1998	9727050
amino acid-amino acid contacts at the cooperativity interface of the bacteriophage lambda and p22 repressors.	the bacteriophage lambda repressor and its relatives bind cooperatively to adjacent as well as artificially separated operator sites. this cooperativity is mediated by a protein-protein interaction between the dna-bound dimers. here we use a genetic approach to identify two pairs of amino acids that interact at the dimer-dimer interface. one of these pairs is nonconserved in the aligned sequences of the lambda and p22 repressors; we show that a lambda repressor variant bearing the p22 residues a ...	1998	9732276
efficient display of an hcv cdna expression library as c-terminal fusion to the capsid protein d of bacteriophage lambda.	we describe the construction and characterization of a hepatitis c virus (hcv) cdna expression library displayed as a fusion to the carboxy terminus of the capsid protein d of bacteriophage lambda. cdna inserts were obtained by tagged random-priming of the hcv genome and cloned into a lambda vector from which chimeric phage bearing both wild-type d protein and d fusion products on the capsid surface were produced. the resulting library was affinity-selected with anti-hcv human monoclonal antibod ...	1998	9733645
replication and maintenance of lambda plasmids devoid of the cro repressor autoregulatory loop in escherichia coli.	plasmids derived from bacteriophage lambda are known as lambda plasmids. these plasmids contain the ori lambda region and lambda replication genes o and p. typical lambda plasmids also contain the cro gene, the product of which is a repressor of the pr promoter when present at relatively high concentrations. these genes stably maintain the plasmid in escherichia coli at copy numbers of 20 to 50 per cell. according to a generally accepted model, stable maintenance of lambda plasmids is possible d ...	1998	9735313
the use of oric-dependent phage infection to characterize the ultra violet (uv)-induced inhibition of initiation of dna replication in escherichia coli.	the oric transducing phage lambda poricc is a pseudovirulent phage capable of forming plaques on a lambda lysogen. this phenotype is dependent upon the presence of the oric insert. the ability of lambda poricc to form plaques on a lambda lysogen represents a potential phage assay system for studying aspects of oric function. in the present study we establish that lambda poricc infection of a lambda lysogen is a legitimate assay for oric function. we use this assay to confirm the previously repor ...	1998	9739817
dnaa-mediated regulation of phage lambda-derived replicons in the absence of pr and cro function.	bacteriophage lambda-derived replicons can replicate in escherichia coli cells as plasmids. in the control of replication of these plasmids, an important role was ascribed to the lambda cro repressor autoregulatory loop. however, the or/pr-cro-tr-cii' region could be replaced by the pteta promoter under the control of the tetr repressor, producing plasmid ptclambda. here, we demonstrate that stable maintenance of ptclambda depends on the host dnaa function because deletion of one of dnaa-binding ...	1998	9740781
phylogenetic position and codon usage of two centrin genes from the rumen ciliate protozoan, entodinium caudatum.	a lambda phage cdna expression library was constructed from washed suspensions of the rumen ciliate protozoan, entodinium caudatum, which had been maintained in an isolated, monofaunated sheep. the library was screened using an anti-e. caudatum antiserum raised in rabbits against sonically disrupted protozoa, dna sequences for two centrins or caltractins, a subfamily of the ef-hand ca(2+)-modulated proteins which are closely related, highly conserved cytoskeletal proteins, were identified and ch ...	1998	9741093
cloning and characterization of the dnak heat shock operon of the marine bacterium vibrio harveyi.	we cloned the dna region of the vibrio harveyi chromosome containing the heat shock genes dnak and dnaj and sequenced them. these genes are arranged in the chromosome in the order dnak-dnaj, as in other proteobacteria of the alpha and gamma subdivisions. the dnak gene is 1923 nucleotides in length and codes for a protein of 640 amino acid residues, with a predicted molecular mass of 69,076 da and 81.2% similarity to the dnak protein of escherichia coli. the v. harveyi dnaj gene has a coding sequ ...	1998	9747709
[lethal and mutagenic effects of tritium incorporated into position 8 of the purines in phage lambda dna and the role of the fpg protein].	the lethal and mutagenic effects of the decay of 3h incorporated in phage lambda dna as 8-3h-adenosine and 8-3h-guanosine were studied, using the dna of 8-3h-adenine as a labeled dna precursor. a transmutation component of 3h decay is involved in formation of 8-oxoguanine (8-oxo-g) and 8-oxoadenine (8-oxo-a) residues in phage dna. the efficiency of phage inactivation (the number of lethal lesions per one tritium decay in the phage genome) for 3h decay in position 8 of purines was the same as tha ...	1998	9749331
thermal melting properties of c-terminal domain mutants of bacteriophage lambda ci repressor.		1998	9750232
cooperative non-specific dna binding by octamerizing lambda ci repressors: a site-specific thermodynamic analysis.	relationships between dimerization and site-specific binding have been characterized previously for wild-type and mutant ci repressors at the right operator (or) of bacteriophage lambda dna. however, the roles of higher-order oligomers (tetramers and octamers) that are also formed from these ci molecules have remained elusive. in this study, a clear correlation has been established between repressor oligomerization and non-specific dna-binding activity. a modification of the quantitative dnase i ...	1998	9753546
single-step purification and characterization of mbp (maltose binding protein)-dnaj fusion protein and its utilization for structure-function analysis.	dnaj is a molecular chaperone, which contains a zinc finger-like motif and cooperates with dnak to mediate the folding of newly synthesized and denatured proteins. dnaj was overproduced and purified using the maltose binding protein (mbp) fusion vector. the fusion protein (mbp-dnaj) was expressed in a soluble form in escherichia coli and purified to homogeneity using amylose resin in a single step. the uv-visible absorption spectrum of mbp-dnaj showed peaks at 355 and 475 nm. moreover, these abs ...	1998	9756632
a procedure for cloning genomic dna fragments with increasing thermoresistance.	genomic dnas have been cleaved by restriction or sonication, and the resulting double-stranded fragments have been exposed to increasing temperatures. this treatment may induce the helix-coil transition either in a single or in several steps, depending on the size and composition of the duplexes. eventually, a critical temperature is reached at which each duplex melts completely and the two constitutive single strands separate. a transition interval can thus be defined for each duplex by the tem ...	1998	9756997
accelerated cyclization of lambda dna.	in the presence of spermidine, the dna molecule of the bacteriophage lambda undergoes a coil-globule transition. we report here that the cyclization of this molecule in its globular state is greatly accelerated (by more than 10(4)-fold) in comparison with the cyclization reaction taking place in the coil conformation.	1998	9759351
the equine estrogen metabolite 4-hydroxyequilenin causes dna single-strand breaks and oxidation of dna bases in vitro.	premarin (wyeth-ayerst) is the estrogen replacement treatment of choice and continues to be one of the most widely dispensed prescriptions in north america. in addition to endogenous estrogens, premarin contains unsaturated equine estrogens, including equilenin [1,3,5(10),6,8-estrapentaen-3-ol-17-one]. in previous work, we showed that the equilenin metabolite 4-hydroxyequilenin (4-ohen) can be autoxidized to 4-ohen-o-quinone which readily entered into a redox couple with the semiquinone radical ...	1998	9760286
cdna cloning and escherichia coli expression of uk114 tumor antigen.	experimental evidence indicates that the antineoplastic effects of uk101, a goat liver perchloric acid extract, is likely due to one of its constituent proteins: the 14 kda protein named uk114. the cdna encoding uk114, obtained by pcr methodologies, contains an open reading frame coding for a protein of 137 amino acids with a theoretical molecular mass of 14298 da. it shows high sequence homology with a 14 kda protein identified in human, rat and mus musculus tissues which is likely involved in ...	1998	9767104
analysis of protein and dna-mediated contributions to cooperative assembly of protein-dna complexes.	the cooperative assembly of protein-dna complexes is a widespread phenomenon that is of particular significance to transcriptional regulation. assembly of these complexes is controlled by the chemistry of the macromolecular interactions. in this sense, transcriptional regulation is a chemical issue. the purpose of this review is to present an analytical approach designed to understand this regulation from a chemical perspective. by investigating the solution interactions between all combinations ...	1998	9774512
high sensitivity for color mutants in lacz plasmid-based transgenic mice, as detected by positive selection.	transgenic mice carrying bacteriophage lambda-based vectors harboring a lacz or laci reporter gene have been used in recent years for the detection, quantification, and characterization of spontaneous and induced gene mutations in vivo. the usefulness of these models is basically determined by their ability to detect significant (organ-specific) exposure-related increases in mutant frequencies. this, in its turn, is dependent on the models' ability to detect all possible types of mutations, incl ...	1998	9776177
a surface of escherichia coli sigma 70 required for promoter function and antitermination by phage lambda q protein.	the sigma initiation factor sigma70 of escherichia coli acts not only in promoter recognition and dna strand opening, but also to mediate the transformation of rna polymerase (rnap) to an antiterminating form by the phage lambda gene q protein. q is able to bind and modify rnap when alpha70, still present in the initially elongating enzyme, recognizes a repeat of the -10 promoter element and induces a transcription pause. we have isolated mutations in the rpod gene for sigma70 that impair q func ...	1998	9784501
escherichia coli dnaa gene function and bacteriophage lambda replication.	allele specificity of the escherichia coli dnaa gene function in the replication of plasmids derived from bacteriophage lambda has been demonstrated previously. here, using a series of dnaa temperature-sensitive mutants, we investigated dnaa allele specificity of the replication of phages lambda p+ and lambda pts 1 pi a66. we found that phage lambda p+ produces its progeny efficiently at 43 degrees c irrespective of the dnaa allele, whereas lambda pts 1 pi a66, which is unable to develop lytical ...	1998	9785448
cloning of follistatin-related protein as a novel autoantigen in systemic rheumatic diseases.	in an attempt to identify autoantigens of synovium in rheumatoid arthritis (ra), we constructed lambda phage expression cdna libraries from synovium and screened them by igg purified from synovial fluids, both of which were derived from ra patients. as a result of this unique combination of the libraries and probes, we cloned follistatin-related protein (frp) as a novel autoantigen in systemic rheumatic diseases. frp is a secreted protein containing a similar amino acid sequence to follistatin, ...	1998	9786430
an evaluation of rapd fragment reproducibility and nature.	random amplified polymorphic dna (rapd) fragment reproducibility was assayed in three animal species: red deer (cervus elaphus), wild boar (sus scrofa) and fruit fly (drosophila melanogaster). ten 10-mer primers (operon) were tested in two replicate reactions per individual under different stringency conditions (annealing temperatures of 35 degrees c or 45 degrees c). two estimates were generated from the data: autosimilarity, which tests the reproducibility of overall banding patterns, and band ...	1998	9787445
participation of ihf and a distant up element in the stimulation of the phage lambda pl promoter.	we have previously identified a up element in the phage lambda pl promoter, centred at position -90 from the transcription start site. integration host factor (ihf), a heterodimeric dna-binding and -bending protein, binds upstream of the lambda pl promoter in a region overlapping the up element. stimulation of transcription by ihf requires an intact alphactd and affects the initial binding of rna polymerase to the promoter. we propose a model for the stimulation of pl by ihf in which ihf bends t ...	1998	9791187
delineation of an evolutionary salvage pathway by compensatory mutations of a defective lysozyme.	model-free approaches (random mutagenesis, dna shuffling) in combination with more "rational," three-dimensional information-guided randomization have been used for directed evolution of lysozyme activity in a defective t4 lysozyme mutant. a specialized lysozyme cloning vector phage, derived from phage lambda, depends upon t4 lysozyme function for its ability to form plaques. the substitution w138p in t4 lysozyme totally abolishes its plaque-forming ability. compensating mutations in w138p t4 ly ...	1998	9792108
the organization of the alpha-tubulin gene family in the drosophila montium subgroup of the melanogaster species group.	the alpha 1-, alpha 2-, alpha 3-, and alpha 4-tubulin genes have been mapped by in situ hybridization to the polytene chromosomes of five species representative of the drosophila montium subgroup geographical distribution. a lambda phage clone containing alpha 1-tubulin specific sequences was isolated from a genomic dna library of drosophila auraria and its restriction endonuclease pattern is presented. both well-characterized heterologous and homologous probes were used to assess orthogonality ...	1998	9796099
an evolutionary link between sporulation and prophage induction in the structure of a repressor:anti-repressor complex.	spore formation is an extreme response of some bacteria to adversity. in bacillus subtilis the proteins of the sin, sporulation inhibition, region form a component of an elaborate molecular circuitry that regulates the commitment to sporulation. sinr is a tetrameric repressor protein that binds to the promoters of genes essential for entry into sporulation and prevents their transcription. this repression is overcome through the activity of sini, which disrupts the sinr tetramer through the form ...	1998	9799632
complete genomic sequence and analysis of the prion protein gene region from three mammalian species.	the prion protein (prp), first identified in scrapie-infected rodents, is encoded by a single exon of a single-copy chromosomal gene. in addition to the protein-coding exon, prp genes in mammals contain one or two 5'-noncoding exons. to learn more about the genomic organization of regions surrounding the prp exons, we sequenced 10(5) bp of dna from clones containing human, sheep, and mouse prp genes isolated in cosmids or lambda phage. our findings are as follows: (1) although the human prp tran ...	1998	9799790
identification and characterization of the fis operon in enteric bacteria.	the small dna binding protein fis is involved in several different biological processes in escherichia coli. it has been shown to stimulate dna inversion reactions mediated by the hin family of recombinases, stimulate integration and excision of phage lambda genome, regulate the transcription of several different genes including those of stable rna operons, and regulate the initiation of dna replication at oric. fis has also been isolated from salmonella typhimurium, and the genomic sequence of ...	1998	9811652
lambda rap protein is a structure-specific endonuclease involved in phage recombination.	bacteriophage lambda encodes a number of genes involved in the recombinational repair of dna double-strand breaks. the product of one of these genes, rap, has been purified. truncated rap proteins that copurify with the full-length form are derived, at least in part, from a rho-dependent transcription terminator located within its coding sequence. full-length and certain truncated rap polypeptides bind preferentially to branched dna substrates, including synthetic holliday junctions and d-loops. ...	1998	9811830
interaction of the escherichia coli dnaa protein with bacteriophage lambda dna.	interaction of the escherichia coli dnaa (replication initiator) protein with restriction fragments of phage lambda dna demonstrated differential binding of dnaa along the whole lambda dna. interaction of dnaa with the lambda replication region (from the promoter pr to the origin of replication, orilambda) demonstrated a strong binding of dnaa to the region around the p(o) promoter where synthesis of a short antisense oop rna is initiated. the four sequences protected by dnaa (two 9mers and two ...	1998	9819062
cloning of the j gene of bacteriophage lambda, expression and solubilization of the j protein: first in vitro studies on the interactions between j and lamb, its cell surface receptor.	bacteriophage lambda adsorbs to its escherichia coli k12 host by interacting with a specific cell surface receptor, the outer membrane protein lamb. previous genetic analyses led us to define a set of residues at the surface of lamb, which belong to the lambda receptor site. further genetic studies indicated that the c-terminal portion of j, the tail fibre protein of lambda, was directly involved in the recognition of the receptor site. the present work describe first in vitro studies on the int ...	1998	9826917
co-expression of yeast amber suppressor trnatyr and tyrosyl-trna synthetase in escherichia coli: possibility to expand the genetic code.	an efficient system was developed for the co-expression of a yeast trnatyr/tyrosyl-trna synthetase (tyrrs) pair in escherichia coli. analysis of suppression patterns using several sets of e. coli and lambda phage mutants indicated that the expressed yeast suppressor trnatyr was aminoacylated only with tyrosine by its cognate yeast tyrrs and not by e. coli tyrrs or other aminoacyl-trna synthetases. this extra trna/tyrrs pair is expected to be a key bridgehead for developing an in vivo system for ...	1998	9832608
isolation of frog and chicken cdnas encoding heparin cofactor ii.	heparin cofactor ii (hcii) is a serpin that inhibits thrombin rapidly in the presence of heparin or dermatan sulfate. hcii activity has been detected in human, rabbit, and mouse plasma, and cdna clones for hcii have been isolated previously from human, rabbit, rat, and mouse liver libraries, suggesting a conserved physiologic role for hcii among mammals. in this report, we show that both frog and chicken plasma contain a dermatan sulfate-dependent inhibitor that forms a 118-kda complex with huma ...	1998	9843172
vectors for transcription factor cloning and target site identification by means of genetic selection in yeast.	we describe the construction of a number of vectors that can be used in yeast genetic selection systems for cloning of transcription factors or other dna-binding proteins and for identification of the target sites recognized by transcription factors. for transcription factor cloning we have designed an integration vector with two his3 reporter gene cassettes to stably integrate reporter gene constructs at the non-essential yeast pdc6 locus. this set of plasmids was tested in a one-hybrid assay w ...	1998	9848232
recombination in phage lambda: one geneticist's historical perspective.	several features of bacteriophage lambda suit it for the study of genetic recombination. central among them are those that make it possible to correlate inheritance of dna with the inheritance of information encoded by dna through density-label equilibrium centrifugation. such studies have revealed relationships between dna replication and recombination, have identified roles for double-strand breaks in the initiation of recombination, and have elucidated the role of the recombination-stimulatin ...	1998	9858698
from bacteriophage lambda to nonlinear dynamics.	thirty years ago, waclaw and myself were working on the same organism and had the same type of interest. since that happy time, our trajectories have diverged so much that i am afraid any paper i might offer for his jubilee would seem completely strange and irrelevant to him and as well to his colleagues. for this reason, i decided rather to offer waclaw, as a modest present, a product of my recent work which i consider, perhaps presumptuously, as an 'oeuvre d'art' (of course, this qualification ...	1998	9858701
acquired mutations in phage lambda genes o or p that enable constitutive expression of a cryptic lambdan+ci[ts]cro- prophage in e. coli cells shifted from 30 degreesc to 42 degreesc, accompanied by loss of immlambda and rex+ phenotypes and emergence of a non-immune exclusion-state.	the majority of bacteria, which carry the n+-ci857[ts]-cro--o+-p+ fragment of lambda genome, are killed when derepressed by shifting from 30 degreesc to 42 degreesc. among rare survivors, we observed a proportion of colony-forming units (cfu) that retained the typical immlambda-immunity phenotype when grown at 30 degreesc; however, when shifted from 30 degreesc to 42 degreesc, they lost lambda immunity and acquired a non-immune exclusion-state (nie phenotype). we also found that the immlambda su ...	1998	9858705
formation of the preprimosome protects lambda o from rna transcription-dependent proteolysis by clpp/clpx.	using the bacteriophage lambda dna replication system, composed entirely of purified proteins, we have tested the accessibility of the short-lived lambda o protein to the clpp/clpx protease during the various stages of lambda dna replication. we find that binding of lambda o protein to its orilambda dna sequence, leading to the so-called "o-some" formation, largely inhibits its degradation. on the contrary, under conditions permissive for transcription, the lambda o protein bound to the orilambd ...	1998	9860956
rexb of bacteriophage lambda is an anti-cell death gene.	in escherichia coli, programmed cell death is mediated through "addiction modules" consisting of two genes; the product of one gene is long-lived and toxic, whereas the product of the other is short-lived and antagonizes the toxic effect. here we show that the product of lambdarexb, one of the few genes expressed in the lysogenic state of bacteriophage lambda, prevents cell death directed by each of two addiction modules, phd-doc of plasmid prophage p1 and the rel mazef of e. coli, which is indu ...	1998	9860994
bacteriophage lambda surface display of a bacterial biotin acceptor domain reveals the minimal peptide size required for biotinylation.	phage display is a powerful technique for identifying specific ligands to a given target. in this work random peptides derived from the biotin accepting domain of the klebsiella pneumoniae oxaloacetate decarboxylase were displayed on bacteriophage lambda heads to determine the minimal sequence length that is necessary to effect biotinylation in vivo. phages with a functional biotinylation domain were identified after affinity purification with immobilised avidin. all biotinylated phages isolated ...	1998	9862457
dnak-dependent ribosome biogenesis in escherichia coli: competition for dominance between the alleles dnak756 and dnak+.	the escherichia coli chaperone dnak is vital for many cellular functions, including ribosome biogenesis at high temperature. thus, the dnak756-ts (lambdar) mutant, at the non-permissive temperature, is inhibited at a late stage of ribosome assembly, yielding 21s, 32s and 45s precursor particles. this defect, unlike the lambda resistance and thermosensitivity phenotypes, is not complemented by lysogenisation with a transducing phage lambda dnak+ bearing the wild-type dnak gene. however this domin ...	1998	9862472
prediction of selectivity for the separation of double-stranded dna fragments in electrophoresis.	the electrophoretic resolution (selectivity) of double-stranded dna (dsdna) restriction fragments is studied for different organisms (phi x174, lambda phage, and pgem-3 plasmids) by various separation and detection methods. the selectivity can be predicted by plotting the difference in chain length over their average chain length (base pair difference/average base pair magnitude of delta bp/ave.-bp) against each dna fragment pair. experimental conditions and the nature of the dna can influence t ...	1997	9725123
clustering of chi sequence in escherichia coli genome.	an 8-mer dna sequence called chi (5'-gctggtgg) is present on the escherichia coli chromosome at a high frequency. it is responsible for both the attenuation of recbcd exonuclease activity and the promotion of recabcd-mediated homologous recombination. chi was first identified as a site that increased plaque size of bacteriophage lambda. lambda containing chi makes very small plaques on a recc* (recc1004) mutant because chi is poorly recognized by the recbc*d mutant enzyme. we cloned e. coli chro ...	1997	9689227
amplification of psc101 replicons in escherichia coli during amino acid limitation.	amino acid starvation of escherichia coli rela mutants was previously proposed as a method for efficient amplification of plasmids bearing origin of replication derived from cole1-type plasmids and bacteriophage lambda. here we demonstrate that plasmids derived from psc101 replicon can be amplified in e. col rela+ and rela- strains during amino acid limitation but not during amino acid starvation. the amplification efficiency is dependent on temperature (37 degrees c was found to be the optimal ...	1997	9470225
a new dna vehicle for nonviral gene delivery: supercoiled minicircle.	plasmids currently used for nonviral gene transfer have the disadvantage of carrying a bacterial origin of replication and an antibiotic resistance gene. there is, therefore, a risk of uncontrolled dissemination of the therapeutic gene and the antibiotic resistance gene. minicircles are new dna delivery vehicles which do not have such elements and are consequently safer as they exhibit a high level of biological containment. they are obtained in e. coli by att site-specific recombination mediate ...	1997	9472558
[the factors controlling different activity of dna-polymerases from thermus thermophilus and thermus aquaticus in process of amplification of phage lambda dna].		1997	9480430
the xcpr protein of pseudomonas aeruginosa dimerizes via its n-terminus.	extracellular protein secretion by the main terminal branch of the general secretory pathway in pseudomonas aeruginosa requires a secretion machinery comprising the products of at least 12 genes. one of the components of this machinery, the xcpr protein, belongs to a large family of related proteins distinguished by the presence of a highly conserved nucleotide binding domain (walker box a). the xcpr protein is essential for the process of extracellular secretion and amino acid substitutions wit ...	1997	9426126
mutation of d. radiodurans in a gene homologous to ruvb of e. coli.	following the digestion of chromosomal dna of deinococcus radiodurans with a restriction enzyme a partial genomic library was constructed using lambda phage as a vector. a phage clone whose dna can complement the deficiency in a radiation-sensitive mutant of d. radiodurans was isolated. following the subcloning using phasmid vector, a hybrid plasmid containing 1.2 kb inserted dna was obtained. after the determination of nucleotide sequence, the deduced amino acid sequence showed close homology t ...	1997	9447236
immunological screening of lambda-phage cdna expression libraries.		1997	9116850
protein interaction cloning by far-western screening of lambda-phage cdna expression libraries.		1997	9116852
a full-length and replication-competent proviral clone of sivagm from tantalus monkeys.	african green monkeys (agm) are classified into four distinct species (commonly termed vervet, grivet, sabaeus, and tantalus monkeys), all of which are known to be infected with simian immunodeficiency virus (sivagm) in the wild. sequence analysis of partial gag and env regions has indicated that each of the four species harbors a phylogenetically distinct sivagm subtype. this species-specific diversity suggests that african green monkeys have been infected with sivagm for an extended period of ...	1997	9123848
structure and organization of gabrb3 and gabra5.	the genes encoding the gamma-aminobutyric acid (gaba) type-a receptor subunits beta 3 (gabrb3), alpha 5 (gabra5), and gamma 3 (gabrg3) map to chromosome 15q11-q13. the three genes are contained within roughly 800 kb of the distal part of the imprinted prader-willi and angelman syndrome region. a 570-kb contig encompassing gabrb3 and gabra5 has been constructed in p1, lambda phage, and pac clones. gabrb3 spans 250 kb of dna and is organized into 9 exons that range from 68 to 504 bp, while gabra5 ...	1997	9126483
the molecular basis for cross-reaction of an anti-dystrophin antibody with alpha-actinin.	the epitope recognised by the anti-dystrophin monoclonal antibodies mandys141 and mandys142 has been characterised using a phage display peptide library and a bacteriophage lambda cdna library. using a phage display library of random 15-mer peptides, the epitope recognised by the two antibodies was identified as eexf. a lambda gt11 clone obtained by screening a human muscle cdna library was shown to contain part of the out-of-frame human mitochondrial succinyl coa synthetase (alpha-subunit) cdna ...	1997	9128182
the oligomeric structure of nucleoid protein h-ns is necessary for recognition of intrinsically curved dna and for dna bending.	escherichia coli hns, encoding the abundant nucleoid protein h-ns, was subjected to site-directed mutagenesis either to delete pro115 or to replace it with alanine. unlike the wild-type protein, hyperproduction of the mutant proteins did not inhibit macromolecular syntheses, was not toxic to cells and caused a less drastic compaction of the nucleoid. gel shift and ligase-mediated circularization tests demonstrated that the mutant proteins retained almost normal affinity for non-curved dna, but l ...	1997	9130723
rapid mapping and subcloning of genomic clones in bacteriophage lambda by pcr.		1997	9149854
clone-contig and sts maps of the hereditary hemochromatosis region on human chromosome 6p21.3-p22.	yac-based and bacterial-clone based sts-content maps were constructed that served as the framework physical maps for the positional cloning of a candidate gene for hereditary hemochromatosis. the yac-based map comprises 43 yacs and 86 sts and spans approximately 8 mb of dna between the class i region of the major histocompatibility complex on human chromosome 6p21.3 and d6s276 in 6p22. comparison with published maps revealed a hole in the mit/whitehead and ceph yac maps that includes the immedia ...	1997	9149942
impaired lysogenisation of the escherichia coli rpoa341 mutant by bacteriophage lambda is due to the inability of cii to act as a transcriptional activator.	the c-terminus of the alpha subunit of escherichia coli rna polymerase is known to function in transcriptional activation at certain promoters. this region was previously shown to be necessary for full activation of the pe promoter by the phage lambda cii protein in vitro. in this work we investigated the inability of phage lambda to follow the lysogenic pathway in cells carrying the point mutation rpoa341 (a change of lysine 271 to glutamic acid). we found that neither overexpression of the cii ...	1997	9150265
identification of an hd patient with a (cag)180 repeat expansion and the propagation of highly expanded cag repeats in lambda phage.	the huntington's disease mutation has been identified as a cag/polyglutamine repeat expansion in a large gene of unknown function. in order to develop the transgenic systems necessary to uncover the molecular pathology of this disorder, it is necessary to be able to manipulate highly expanded cag repeats in a cloned form. we have identified a patient with an expanded allele of greater than 170 repeat units and have cloned the mutant allele in the lambda zap vector. the recovery of highly expande ...	1997	9150744
kinetic analysis of the endonuclease activity of phage lambda terminase: assembly of a catalytically competent nicking complex is rate-limiting.	the terminase enzyme from bacteriophage lambda is responsible for excision of a single genome from a concatameric dna precursor and its insertion into an empty viral procapsid. the enzyme possesses a site-specific endonuclease activity which is responsible for excision of the viral genome and the formation of the 12 base-pair single-stranded "sticky" ends of mature lambda dna. we have previously reported a kinetic analysis of the endonuclease activity of lambda terminase which showed an enzyme c ...	1997	9153418
mnk1, a new map kinase-activated protein kinase, isolated by a novel expression screening method for identifying protein kinase substrates.	we have developed a novel expression screening method for identifying protein kinase substrates. in this method, a lambda phage cdna expression library is screened by in situ, solid-phase phosphorylation using purified protein kinase and [gamma-32p]atp. screening a hela cdna library with erk1 map kinase yielded cdnas of previously characterized erk substrates, c-myc and p90rsk, demonstrating the utility of this method for identifying physiological protein kinase substrates. a novel clone isolate ...	1997	9155018
the dual role of apl in prophage induction of coliphage 186.	in the present study we show that the apl protein of the temperate coliphage 186 combines, in one protein, the activities of the coliphage lambda proteins cro and xis. we have shown previously that apl represses both the lysogenic promoter, pl, and the major lytic promoter, pr, and is required for excision of the prophage. apl binds at two locations on the phage chromosome, i.e. between pr and pl and at the phage-attachment site. using an in vivo recombination assay, we now show that the role of ...	1997	9157239
genome structure of pti-sakura (i): strategy for dna sequencing of a japanese cherry-ti plasmid.	we isolated a plasmid from a bacterium agrobacterium tumefaciens, which had been found in a crown gall tumor on a japanese cherry tree sakura and designated it pti-sakura. for complete dna sequencing, we constructed a dna library in lambda phage vector and developed a sequencing method by primer walking with long pcr and a pcr subcloning technique for long insert dna.	1997	9586048
cloning of the glutamine synthetase gene from group b streptococci.	the glna gene from the human pathogen streptococcus agalactiae was cloned from a genomic library prepared with the lambda phage vector lambdadashii. a 4.6-kb dna fragment of one of the recombinant phages was subcloned in puc18. this escherichia coli clone expressed a 52-kda protein encoded by a 1,341-bp open reading frame. the nucleotide sequence of the open reading frame and the deduced amino acid sequence shared a significant degree of homology with the sequences of other glutamine synthetases ...	1997	8975911
the hflb protease of escherichia coli degrades its inhibitor lambda ciii.	the ciii protein of bacteriophage lambda is known to protect two regulatory proteins from degradation by the essential escherichia coli protease hflb (also known as ftsh), viz., the lambda cii protein and the host heat shock sigma factor sigma32. lambda ciii, itself an unstable protein, is partially stabilized when the hflb concentration is decreased, and its half-life is decreased when hflb is overproduced, strongly suggesting that it is degraded by hflb in vivo. the in vivo degradation of lamb ...	1997	8990286
analysis of bacteriophage n protein and peptide binding to boxb rna using polyacrylamide gel coelectrophoresis (pace).	the antitermination protein n from bacteriophage lambda (nlambda) interacts with the nut site in its own mrna, as well as host factors, to facilitate formation of a termination-resistant transcription complex. the conserved, amino-terminal arginine-rich domain of nlambda protein is known to interact with a small rna hairpin (boxb) derived from the nut site rna. we have examined the binding of nlambda protein, peptides derived from the amino terminus of nlambda, and the related phage p22 n protei ...	1997	8990399
structure and transcription of the gene for translation elongation factor 1 subunit alpha of zebrafish (danio rerio).	the zebrafish gene for translation elongation factor 1 alpha (ef1 alpha) was isolated from a phage lambda genomic library and sequence and structure determined. one gene copy of ef1 alpha per haploid set of chromosomes was found and no processed pseudogenes. a highly active promoter region was localized to a 277 bp psti/pvuii fragment beginning 240 bp upstream from the tsp, but no transcription enhancing, or silencing activity was observed within 1 kbp upstream, or downstream from the promoter. ...	1997	9003448
isolation and characterization of the integration host factor genes of pasteurella haemolytica.	using a bacteriophage lambda complementation system in escherichia coli, we cloned genes encoding subunits of the heterodimeric dna binding/bending protein, integration host factor, from the bovine pathogen, pasteurella haemolytica. complementation of ihfa and ihfb mutations in e. coli demonstrated that the p. haemolytica gene products form functional heterologous heterodimers. the ihfa and ihfb genes encode polypeptides predicted to be 99 and 93 amino acids long, respectively, and are very simi ...	1997	9011038
structure of dna-cationic liposome complexes: dna intercalation in multilamellar membranes in distinct interhelical packing regimes.	cationic liposomes complexed with dna (cl-dna) are promising synthetically based nonviral carriers of dna vectors for gene therapy. the solution structure of cl-dna complexes was probed on length scales from subnanometer to micrometer by synchrotron x-ray diffraction and optical microscopy. the addition of either linear lambda-phage or plasmid dna to cls resulted in an unexpected topological transition from liposomes to optically birefringent liquid-crystalline condensed globules. x-ray diffract ...	1997	9012343
the activation defect of a lambda ci positive control mutant.	"positive control" mutants of the ci protein of bacteriophage lambda (lambda ci) bind dna but, unlike the wild-type protein, fail to activate transcription. according to the original interpretation of ptashne and co-workers, these mutants bear amino acid substitutions that disrupt a stimulatory interaction between lambda ci bound at operator site o(r)2 and rna polymerase bound at promoter p(rm), an idea supported by kinetic analysis in one case. genetic analysis has suggested that one residue in ...	1997	9018040
the ynt1 gene encoding the nitrate transporter in the yeast hansenula polymorpha is clustered with genes yni1 and ynr1 encoding nitrite reductase and nitrate reductase, and its disruption causes inability to grow in nitrate.	dna sequencing in the phage lambda ja13 isolated from a lambda embl3 hansenula polymorpha genomic dna library containing the nitrate reductase-(ynr1) and nitrite reductase-(yni1) encoding genes revealed an open reading frame (ynt1) of 1524 nucleotides encoding a putative protein of 508 amino acids with great similarity to the nitrate transporters from aspergillus nidulans and chlamydomonas reinhardtii. disruption of the chromosomal ynt1 copy resulted in incapacity to grow in nitrate and a signif ...	1997	9020872
a single 13-kilobase divergent locus in the kaposi sarcoma-associated herpesvirus (human herpesvirus 8) genome contains nine open reading frames that are homologous to or related to cellular proteins.	two small fragments of a novel human gammaherpesvirus genome known as kaposi's sarcoma (ks)-associated herpesvirus or human herpesvirus 8 (hhv-8) have been shown to be present in virtually all aids and non-aids ks lesions, as well as in body cavity-based lymphomas (bcbl) and in multicentric castleman's disease. we have extended those studies by identifying and sequencing a third fragment of hhv-8 dna encoding a viral thymidylate synthetase (ts) gene. use of this viral ts fragment as a probe led ...	1997	9032328
a novel bacterial vector system for monitoring protein-protein interactions in the camp-dependent protein kinase complex.	a bacterial expression vector is described for investigation of protein-protein interactions. important features of the vector include partition of the ci repressor of bacteriophage lambda into two functional domains separated by a multicloning site, and low level auto-regulated expression of human genes as c-terminal fusions to the dna-binding domain of ci. two different reporter systems have been employed; expression of either a suppressor trna or the alkaline phosphatase gene is dependent in ...	1997	9034306
efficient epitope mapping by bacteriophage lambda surface display.	a bacteriophage lambda surface expression system, lambda foo, was used for epitope mapping of human galectin-3. we constructed random epitope and peptide libraries and compared their efficiencies in the mapping. the galectin-3 cdna was randomly digested by dnase 1 to make random epitope libraries. the libraries were screened by affinity selection using a microtiter plate coated with monoclonal antibodies. direct dna sequencing of the selected clones defined two distinct epitope sites consisting ...	1997	9035110
cryptic single-stranded-dna binding activities of the phage lambda p and escherichia coli dnac replication initiation proteins facilitate the transfer of e. coli dnab helicase onto dna.	the bacteriophage lambda p and escherichia coli dnac proteins are known to recruit the bacterial dnab replicative helicase to initiator complexes assembled at the phage and bacterial origins, respectively. these specialized nucleoprotein assemblies facilitate the transfer of one or more molecules of dnab helicase onto the chromosome; the transferred dnab, in turn, promotes establishment of a processive replication fork apparatus. to learn more about the mechanism of the dnab transfer reaction, w ...	1997	9037022
on the origin of spontaneous somatic mutations and sectored plaques detected in transgenic mice.	the use of transgenic mice with bacterial genes that can be readily recovered and analysed for mutation has made it possible to measure mutant frequencies in many tissues. the mutations are detected by packaging the murine dna into lambda phage and then growing these phage on a bacterial lawn under conditions such that the mutants are distinguishable from nonmutants. in the laci mouse assay, the mutant plaques are blue whereas the nonmutant plaques are clear. the mutations detected in the laci b ...	1997	9042411
an rna polymerase alpha subunit mutant impairs n-dependent transcriptional antitermination in escherichia coli.	we show that the rpoa341 mutation in the gene encoding the alpha subunit of escherichia coli rna polymerase results in a decreased level of transcripts originating from the lytic promoters pl and pr of infecting lambda phage. however, using lacz fusions we demonstrate that initiation of transcription from both pl and pr is not impaired in the rpoa341 host. rather, it is the level of the longer, antiterminated pl- and pr-derived transcripts which is altered: the activity of beta-galactosidase in ...	1997	9044255
molecular and cytological analysis of a mariner transposon from hessian fly.	degenerate pcr primers for conserved regions of the mariner transposase have been shown to amplify dna sequences from the hessian fly (mayetiola destructor). using one of these sequences as a hybridization probe, a clone from an m. destructor genomic library in phage lambda was recovered and sequenced. a transposable element, desmar 1, with perfect inverted terminal repeats and an open reading frame that encodes a mariner class transposase was found. when compared to mariner sequences in the gen ...	1997	9048446
assembly of a nucleoprotein complex required for dna packaging by bacteriophage lambda.	a critical step in the assembly of bacteriophage lambda is the excision of a single genome from a concatemeric dna precursor and insertion of genomic dna into an empty viral capsid. dna packaging is mediated by the lambda proteins gpnu1 and gpa, which form an enzyme complex known as terminase. initiation of the packaging process requires assembly of the terminase subunits onto cos, the lambda dna packaging sequence, and nicking of the duplex, thus forming the 12-base-pair "sticky" ends of the ma ...	1997	9062101
complexes of n antitermination protein of phage lambda with specific and nonspecific rna target sites on the nascent transcript.	the mechanisms that control n protein dependent antitermination in phage lambda have counterparts in many eukaryotic systems, including specific regulatory interactions of the antitermination protein with the nascent rna transcript. here we describe the specific and nonspecific rna binding modes of antitermination protein n. these modes differ markedly in rna binding affinity and in structure. n protein, either free in solution or as a complex with nonspecific rna, lacks observable secondary and ...	1997	9063900
in vitro mutagenicity of the plasmacytomagenic agent pristane (2,6,10,14-tetramethylpentadecane).	pristane is known to induce a distinct type of b-cell-derived malignant lymphoma, plasmacytoma, after administration into the peritoneal cavity of genetically susceptible balb/canpt mice. since the mechanism of pristane-induced plasmacytoma development is poorly understood, we chose to examine the possibility that pristane is mutagenic in rodent cells and decided to use bacteriophage lambda-derived laci/lacz genes as target/reporter to quantitate mutagenesis. here we show that in vitro exposure ...	1997	9065804
modulation of ecoki restriction in vivo: role of the lambda gam protein and plasmid metabolism.	two novel types of alleviation of dna restriction by the ecoki restriction endonuclease are described. the first type depends on the presence of the gam gene product (gam protein) of bacteriophage lambda. the efficiency of plating of unmodified phage lambda is greatly increased when the restricting escherichia coli k-12 host carries a gam+ plasmid. the effect is particularly striking in wild-type strains and, to a lesser extent, in the presence of sbcc and reca mutations. in all cases, gam-depen ...	1997	9068628
cloning and characterization of bacteriophage-like dna from haemophilus somnus homologous to phages p2 and hp1.	in an attempt to identify and characterize components of a heme uptake system of haemophilus somnus, an escherichia coli cosmid library of h. somnus genomic dna was screened for the ability to bind hemin (hmb+). the hmb+ phenotype was associated with a 7,814-bp hindiii fragment of h. somnus dna that was subcloned and sequenced. thirteen open reading frames (orfs) were identified, all transcribed in one direction, and transposon mutagenesis identified orf7 as the gene associated with the hmb+ phe ...	1997	9068631