Publications

family values in the age of genomics: comparative analyses of temperate bacteriophage hk022.	hk022 is a temperate coliphage related to phage lambda. its chromosome has been completely sequenced, and several aspects of its life cycle have been intensively studied. in the overall arrangement, expression, and function of most of its genes, hk022 broadly resembles lambda and other members of the lambda family. upon closer view, significant differences emerge. the differences reveal alternative strategies used by related phages to cope with similar problems and illuminate previously unknown ...	1999	10690418
development of a ssrna internal control reagent for an infectious bursal disease virus reverse transcription/polymerase chain reaction-restriction fragment length polymorphism diagnostic assay.	infectious bursal disease virus (ibdv), family birnaviradae, is the etiologic agent of a commercially important, globally distributed, contagious, immunosuppressive disease of young chickens. a restriction enzyme-compatible ssrna internal control was developed for an ibdv reverse transcription/polymerase chain reaction-restriction fragment length polymorphism (rt/pcr-rflp) diagnostic assay. an 841-bp bacteriophage-lambda dna fragment was directionally ligated to 3' and 5' oligonucleotide linkers ...	1999	12968731
preparation of cdna libraries from vascular cells.	the vast majority of past and present efforts in the molecular cloning of expressed sequences involve isolation of clones from cdna libraries constructed in bacteriophage lambda (1,2). as discussed in chapter 6 , screening these cdna libraries using labeled probes remains the most straightforward method to isolate full length cdnas for which some partial sequence information is known. although the availability of high quality reagents and kits over the past decade has made the process of library ...	1999	21341015
recent developments in antibody engineering.	rapid growth in the field of antibody engineering occurred after it was shown that functional antibody fragments could be secreted into the periplasmic space and even into the medium of escherichia coli by fusing a bacterial signal peptide to the antibody's n-terminus (1,2). these findings allowed scientists to transfer the principles of the immune system for producing specific antibodies to a given antigen into a bacterial system (3). it was now possible to establish antibody libraries in e. co ...	1998	21390866
cloning and expression of arog gene of e. coli and its co-expression with phea and tyrb genes.	3-deoxy-d-arabino-heptulonate-7-phosphate synthetase (dahp) is one of the key enzymes in phenylalanine biosynthesis pathway. in e. coli, dahp is encoded by arog gene. in this work, arog was cloned from an e. coli mutant strain resistant to m-fluro-l-phenylalanine (mpf) and p-fluro-l-phenylalanine (ppf) by pcr. the gene was expressed under the control of lambda phage promoter p(r) in p2392 strain of e. coli. distinct band was detected as the product of arog on sds-page. the specific activity in c ...	1998	12167994
bovine ornithine decarboxylase gene: cloning, structure and polymorphisms.	bovine ornithine decarboxylase (odc) genomic clones were isolated from a bacteriophage lambda dash genomic library. a total of 9452 bp sequence was determined which covers the entire sequence of the bovine odc gene. sequence analysis showed that the bovine odc gene consisted of 12 exons which encode a protein identical to that inferred from a bovine odc cdna. comparison of the structure and nucleotide sequence of the bovine, human and mouse odc genes revealed that the gene was highly conserved. ...	1998	10520448
antitermination by bacteriophage lambda q protein.		1998	10384296
structure and mechanism in transcriptional antitermination by the bacteriophage lambda n protein.		1998	10384297
[photosensitized inactivation of plasmid and bacteriophage lambda dna: relative contribution to the lethal effect of monoadducts and diadducts of 8-methoxypsoralen and their repair in sos-induced escherichia coli cells].	the curves of uv (254 nm)-inactivation and inactivation by furocoumarin derivatives + uva radiation (puva) of bacteriophage lambda and biologically active plasmid pbr322 were measured using escherichia coli k12 bacteria with different defects of dna repair system as a ghost. the ratio of mono- and diadducts (interstrand cross-links) of 8-methoxypsoralen was determined that are formed after treating the dna of pbr322 and bacteriophage lambda with puva. it is shown that, on the average, about five ...	1998	10079918
high-level expression of soluble heterologous proteins in the cytoplasm of escherichia coli by fusion to the bacteriophage lambda head protein d.	the bacteriophage lambda head protein d (gpd) is a small major capsid protein (110aa; 11.6kda; pi=5.68, devoid of cysteine residues) that is essential for stable head morphogenesis. we found that a his-tagged derivative of gpd (gphd) is a monomeric protein with efficient expression properties and high resistance towards thermally induced irreversible aggregation. in addition, gphd can be used as a fusion partner for high-level expression of soluble heterologous proteins in the cytoplasm of esche ...	1998	9931426
multiple sample pcr amplification and electrophoretic analysis on a microchip.	polymerase chain reactions (pcrs) were carried out on as many as four dna samples at a time on a microchip device. the pcr products were then analyzed, either individually or together on the same device, by microchip gel electrophoresis. a standard pcr protocol was used to amplify 199- and 500-base pair (bp) regions of bacteriophage lambda dna and 346- and 410-bp regions of e. coli genomic and plasmid dnas, respectively. thermal lysis of the bacteria was integrated into the pcr cycle. a product ...	1998	9868915
gene structures and properties of enzymes of the plasmid-encoded nicotine catabolism of arthrobacter nicotinovorans.	arthrobacter nicotinovorans is a gram-positive aerobic soil bacterium able to grow on nicotine as its sole source of carbon and nitrogen. the initial steps of nicotine catabolism are catalyzed by nicotine dehydrogenase, the l- and d-specific 6-hydroxynicotine oxidases, and ketone dehydrogenase. the genes encoding these enzymes reside on a 160 kb plasmid, pao1. the cccdna of this plasmid was isolated in high purity and reasonable yield. it served as template material for the construction of a lam ...	1998	9878353
adjacent cooperation of proteins on dna are not representative of long-distance interactions.	the ci repressor of bacteriophage lambda is better-fitted to the proximal interactions in which it naturally takes part than to the long-distance cooperative interactions on dna for which it has become representative. the first observation in support of this statement is the ambiguity of an untypical dnaase i footprint which has become a diagnostic for dna circularisation (and thus for the capacity of the protein to control expression at a distance). however, it was also observed without effecti ...	1998	9879466
organisation of the equine immunoglobulin constant heavy chain genes. ii. equine cgamma genes.	the number of immunoglobulin g constant heavy chain genes (cgamma genes) varies broadly among mammalian species, reflecting structural and functional differences between expressed immunoglobulin g (igg) isotypes and allotypes. up to now equine igg isotypes have been defined only at the biochemical and serological level. it is still not clear how many igg isotypes exist in horses and whether there are any allotypes. here, we describe the isolation and characterisation of equine cgamma genes. an e ...	1998	9880104
effect of plating medium and phage storage on mutant frequency and titer in the lambda cii transgenic mutation assay.	we examined several experimental parameters of the lambda ci/cii transgenic mutation assay. in the assay, clear plaque lambda phage mutants are identified in a positive selection scheme following rescue of the lambda/liz shuttle vector from frozen tissues of big blue" transgenic mice. mutant frequency and titer of phage from various tissues of control and enu-treated animals was essentially the same on lb or tb1 plating medium, and storage of isolated dna at 4 degrees c for up to 4 months did no ...	1998	9882006
isolation and characterization of an oligodendrocyte precursor-derived b-cell epitope in multiple sclerosis.	in a search for possible central nervous system-specific autoantigens in multiple sclerosis (ms), a lambda-phage protein expression library was constructed from an oligodendrocyte-precursor cell line. the library was screened with pooled cerebrospinal fluid (csf) from 54 patients with definite ms according to the criteria of poser. pooled csf samples from 44 patients with other neurological diseases including bacterial meningitis and viral encephalitis were used as control. a total of 1,000,000 ...	1998	9450764
evidence for two preferred hairpin folding patterns in d(cgg).d(ccg) repeat tracts in vivo.	unusual dna secondary structures have been implicated in the expansion of trinucleotide repeat tracts that has been found to be responsible for a growing number of human inherited disorders and folate-sensitive fragile chromosome sites. by inserting trinucleotide repeat sequences into a palindromic clamp in lambda phage we are able to investigate their tendencies to form hairpins in vivo in any particular alignment and with odd or even numbers of repeat units in the hairpin. we previously showed ...	1998	9451435
the regulator of nitrate assimilation in ascomycetes is a dimer which binds a nonrepeated, asymmetrical sequence.	the regulation of nitrate assimilation seems to follow the same pattern in all ascomycetes where this process has been studied. we show here by in vitro binding studies and a number of protection and interference techniques that the transcription factor mediating nitrate induction in aspergillus nidulans, a protein containing a binuclear zinc cluster dna binding domain, recognizes an asymmetrical sequence of the form ctcc ghgg. we further show that the protein binds to its consensus site as a di ...	1998	9488449
lambda rna internal standards quantify sensitivity and amplification efficiency of mammalian gene expression profiling.	there is an increasing interest in being able to document simultaneous levels of multiple mrnas from limited amounts of mammalian tissue. the combination of amplified antisense rna (arna) and reverse northern blot analysis is one technology that allows the measurement of relative levels of multiple mrnas. however, potential problems exist with this approach, such as (i) unknown amplification efficiencies and sensitivity of detection, (ii) an inherent 3' bias of amplified products and (iii) cross ...	1998	9762448
characterization of bacteriophage lambda q- mutant for stable and efficient production of recombinant protein in escherichia coli system.	we previously demonstrated that the lambda system integrated into the host chromosome can overcome the instability encountered in continuous operations of unstable plasmid-based expression vectors. high stability of a cloned gene in a lysogenic state and a high copy number in a lytic state provide cloned-gene stability and overexpression in a two-stage continuous operation. but the expression by the commonly used s- mutant lambda was only twice as high as that of the single copy. to increase the ...	1998	10099231
the expression of recombinant genes from bacteriophage lambda strong promoters triggers the sos response in escherichia coli.	the production of several non-related heterologous proteins in recombinant escherichia coli cells promotes a significant transcription of reca and sfia sos dna repair genes. the activation of the sos system occurs when the expression of plasmid-encoded genes is directed by the strong lambda lytic promoters, but not by iptg-controlled promoters either at 37 or at 42 degrees c, and it is linked to an extensive degradation of the proteins after their synthesis. the triggering signal for the sos res ...	1998	10099463
increased expression of a hemimethylated oric binding protein, seqa, in an apha mutant.	in escherichia coli, the origin of dna replication, oric, becomes transiently hemimethylated at the gatc sequences immediately after initiation of replication and this hemimethylated state is prolonged because of its sequestration by a fraction of outer membrane. this sequestration is dependent on a hemimethylated oric binding protein such as seqa. we previously isolated a clone of phage lambda gt11 called hobh, producing a lacz fusion protein which recognizes hemimethylated oric dna. very recen ...	1998	9924983
the gene structure and promoter sequence of mouse hyaluronan synthase 1.	the structure and organization of mouse hyaluronan synthase 1 gene, has1 were determined by direct sequencing of lambda phage clones carrying the entire gene and by application of the long and accurate (la)-pcr method to amplify regions encompassing the exon-intron boundaries and all of the exons. this gene spans about 11kb of genomic dna and consists of 5 exons and 4 introns. a similarity in the exon-intron organization was found between the genes of mouse has1 and xenopus laevis dg42 which was ...	1998	9494089
regulation of proteolysis of the stationary-phase sigma factor rpos.	rpos, the stationary-phase sigma factor of escherichia coli, is responsible for increased transcription of an array of genes when cells enter stationary phase and under certain stress conditions. rpos is rapidly degraded during exponential phase and much more slowly during stationary phase; the resulting changes in rpos accumulation play an important role in providing differential expression of rpos-dependent gene expression. it has previously been shown that rapid degradation of rpos during exp ...	1998	9495753
tetravinyl-tetramethylcyclo-tetrasiloxane (tetravinyl d4) is a mutagen in rat2lambda laci fibroblasts.	small fragments of silicone gels injected intraperitoneally have been used to induce plasmacytomas in genetically susceptible mice. silicone oils, in contrast to silicone gels, are apparently not tumorigenic in the mouse plasmacytoma system. the reason for this difference as well as the mechanism of silicone gel-induced plasmacytoma development is poorly understood. we chose to examine the possibility that low molecular wt silicone compounds such as siloxanes, leaking from the complex silicone g ...	1998	9498283
the beta protein of phage lambda promotes strand exchange.	bacteriophage lambda encodes a 28 kda protein called beta that binds to single-stranded dna and promotes the renaturation of complementary single strands. beta protein fails to bind directly to duplex dna but remains bound to the dna product of renaturation that beta itself catalyzes. these observations led to an examination of the ability of beta protein to promote strand exchange. beta protein caused the replacement of a 43-mer oligonucleotide annealed to m13 circular single-stranded dna by a ...	1998	9500923
the beta protein of phage lambda binds preferentially to an intermediate in dna renaturation.	phage lambda encodes two recombination proteins that are required for homologous recombination in a reca- host strain. of these two recombination proteins, one is an exonuclease whose action on double-stranded dna produces 3' single-stranded ends; the other, called beta protein, is a dna binding protein that promotes the renaturation of complementary single strands. the enzymes of phage lambda provide a model for understanding a recombination pathway called "single-strand annealing". further inv ...	1998	9500924
a genetic screen for the isolation and characterization of site-specific proteases.	site-specific proteolysis is an important regulatory mechanism in basic cellular and viral processes. using the protease of the hiv as a model, a genetic system has been developed for the isolation and characterization of site-specific proteases. the system utilizes the well defined bacteriophage lambda regulatory circuit where the viral repressor, ci, is specifically cleaved to initiate the lysogenic-to-lytic switch. the model system is rapid, highly specific, and demonstrates the ability to is ...	1998	9501175
cloning and expression of a cdna encoding the large subunit of duck replication factor c.	a cdna encoding an avian homologue of the large subunit of replication factor c (rfc-l) has been cloned from a duck liver cdna expression library prepared in bacteriophage lambda. the full length cdna encodes a protein with a predicted size of approximately 130 kda, consistent with the size of the polypeptide detected in duck liver. the duck rfc-l amino acid sequence shares 66.4% and 68.4% identity with mouse and human rfc-l proteins, respectively. we identified a 4kb rfc-l mrna expressed in mos ...	1998	9512663
crystal structure of the lysozyme from bacteriophage lambda and its relationship with v and c-type lysozymes.	like other lysozymes, the bacteriophage lambda lysozyme is involved in the digestion of bacterial walls. this enzyme is remarkable in that its mechanism of action is different from the classical lysozyme's mechanism. from the point of view of protein evolution, it shows features of lysozymes from different classes. the crystal structure of the enzyme in which all tryptophan residues have been replaced by aza-tryptophan has been solved by x-ray crystallography at 2.3 a using a combination of mult ...	1998	9514719
changes in the periplasmic linker and in the expression level affect the activity of toxr and lambda-toxr fusion proteins in escherichia coli.	in order to assess the potentiality of vibrio cholerae toxr protein and of bacteriophage lambda repressor as indicators of the dimerization of periplasmic proteins in escherichia coli, we have constructed a series of plasmids encoding transmembrane fusion proteins. the amino-terminal part, containing the dna binding domain of either toxr or lambda repressor, is located in the cytoplasm and acts as reporter for dimerization. as models of periplasmic proteins we have used alkaline phosphatase (a d ...	1998	9515742
lambda xis degradation in vivo by lon and ftsh.	lambda xis, which is required for site-specific excision of phage lambda from the bacterial chromosome, has a much shorter functional half-life than int, which is required for both integration and excision (r. a. weisberg and m. e. gottesman, p. 489-500, in a. d. hershey, ed., the bacteriophage lambda, 1971). we found that xis is degraded in vivo by two atp-dependent proteases, lon and ftsh (hflb). xis was stabilized two- to threefold more than in the wild type in a lon mutant and as much as six ...	1998	9515930
how cro and lambda-repressor distinguish between operators: the structural basis underlying a genetic switch.	knowledge of the three-dimensional structures of the lambda-cro and lambda-repressor proteins in complex with dna has made it possible to evaluate how these proteins discriminate between different operators in phage lambda. as anticipated in previous studies, the helix-turn-helix units of the respective proteins bind in very different alignments. in cro the recognition helices are 29 a apart and are tilted by 55 degrees with respect to each other, but bind parallel to the major groove of the dna ...	1998	9520383
design and implementation of a qualitative simulation model of lambda phage infection.	motivation: molecular biology databases hold a large number of empirical facts about many different aspects of biological entities. that data is static in the sense that one cannot ask a database 'what effect has protein a on gene b?' or 'do gene a and gene b interact, and if so, how?'. those questions require an explicit model of the target organism. traditionally, biochemical systems are modelled using kinetics and differential equations in a quantitative simulator. for many biological process ...	1998	9520505
cloning and characterization of mouse msox13 cdna.	a novel sry-related cdna, msox13, was isolated from a lambda phage library derived from mouse embryo. the cdna encodes a protein of 595 amino acids containing the sry-type high mobility group (hmg) box and a putative leucine zipper motif. a sequence comparison of msox13 and other type-d sox proteins shows that the leucine zipper and a neighboring glutamine-rich sequence stretch, which was named q box, are well conserved among known type-d sox proteins. the expression of msox13 is restricted to t ...	1998	9524265
crystallization and preliminary x-ray analysis of the dsdna bacteriophage hk97 mature empty capsid.	hk97 is a temperate dsdna bacteriophage of escherichia coli that is structurally similar to phage lambda, with an icosahedral head of triangulation (7) number 7. although the capsids of several large dsdna phages have been studied extensively using a variety of biophysical approaches, no high-resolution structure is available. we have grown crystals of mature but empty bacteriophage hk97 capsids that diffract to at least 3.5 a using synchrotron radiation. the hk97 head ii crystals are the first ...	1998	9527920
guanosine tetraphosphate (ppgpp)-mediated inhibition of the activity of the bacteriophage lambda pr promoter in escherichia coli.	it was previously demonstrated that the activity of bacteriophage lambda promoter pr is decreased in wild-type escherichia coli cells starved for amino acids (during the stringent response). since pr activity is necessary for the transcriptional activation of ori lambda, this leads to inhibition of the replication of plasmids derived from phage lambda. these results led to the proposal that the pr promoter susceptible to control by the stringent response. however, subsequent studies demonstrated ...	1998	9529531
maltose/maltodextrin system of escherichia coli: transport, metabolism, and regulation.	the maltose system of escherichia coli offers an unusually rich set of enzymes, transporters, and regulators as objects of study. this system is responsible for the uptake and metabolism of glucose polymers (maltodextrins), which must be a preferred class of nutrients for e. coli in both mammalian hosts and in the environment. because the metabolism of glucose polymers must be coordinated with both the anabolic and catabolic uses of glucose and glycogen, an intricate set of regulatory mechanisms ...	1998	9529892
studies on the heterologous expression of bstvi restriction endonuclease in escherichia coli.	bacterial restriction and modification systems must be regulated to avoid self-restriction. it is generally accepted that cognate dna methyltransferases normally protects both, the host's chromosome and extrachromosomal elements from the activity of their endonuclease counterparts. when the bstvirm genes from bacillus stearothermophilus v were subcloned into escherichia coli, several clones exhibiting a r+m- phenotype were originated. the present work was undertaken to analyze the possibility th ...	1998	9530521
characterization of the haemolytic activity of streptococcus equi.	the haemolytic activity of streptococcus equi, the cause of equine strangles, was characterized. production of haemolysin in todd hewitt broth was dependent on an equine serum supplement and the logarithmic phase of growth after which activity declined sharply. rna core also induced haemolysin production from cells harvested at the end of the logarithmic phase of growth. haemolysis was not affected by cholesterol, was only slightly increased in reducing conditions and was completely inactivated ...	1998	9533893
dnaa-stimulated transcriptional activation of orilambda: escherichia coli rna polymerase beta subunit as a transcriptional activator contact site.	we present evidence that escherichia coli rna polymerase beta subunit may be a transcriptional activator contact site. stimulation of the activity of the pr promoter by dnaa protein is necessary for replication of plasmids derived from bacteriophage lambda. we found that dnaa activates the pr promoter in vitro. particular mutations in the rpob gene were able to suppress negative effects that certain dnaa mutations had on the replication of lambda plasmids; this suppression was allele-specific. w ...	1998	9539721
dna breakage by l-dopa and cu(ii): breakage by melanin and bacteriophage inactivation.	we have previously shown that l-dopa in the presence of cu(ii) caused dna cleavage through the generation of reactive oxygen species such as the hydroxyl radical. since l-dopa is the precursor for the synthesis of melanin, we have studied the action of melanin on dna in a similar reaction. in this paper, we show that melanin in the presence of cu(ii) also causes dna strand breakage. however, the rate of such strand breakage is considerably less than l-dopa. melanin and l-dopa are both capable of ...	1998	9541640
interaction between n-terminal domain of h4 and dna is regulated by the acetylation degree.	to study whether the acetylation of one or more of the four acetylatable lysines of histone h4 affects its binding to dna, we have designed a protection experiment with a model system consisting in phage lambda dna as substrate, stui as restriction endonuclease and histone h4 with different degrees of acetylation as the protective agent. it can be deduced from the experimental data that the protection afforded by the histone is not dependent on the number of positive charges lost by acetylation. ...	1998	9545542
[gene introduction into animal tissues by fusogenic liposomes].	the future success of gene therapy relies largely upon the development of ideal gene-transfer vehicles (vectors) that can efficiently and stably introduce and express therapeutic genes into non-dividing tissue cells. we have developed a fusogenic liposome that can deliver the encapsulated dna into the cytoplasm through fusion with the cell membrane. for targeting the dna into the nucleus, we attend to lambda phage particles that encapsulate up to 48 kbp dna in their small head (55 nm in diameter ...	1998	9549362
use of bacteriophage lambda recombination functions to promote gene replacement in escherichia coli.	replacement of escherichia coli's recbcd function with phage lambda's red function generates a strain whose chromosome recombines with short linear dna fragments at a greatly elevated rate. the rate is at least 70-fold higher than that exhibited by a recbc sbcbc or recd strain. the value of the system is highlighted by gene replacement with a pcr-generated dna fragment. the deltarecbcd::plac-red kan replacement allele can be p1 transduced to other e. coli strains, making the hyper-rec phenotype ...	1998	9555887
specific binding of escherichia coli ribosomal protein s1 to boxa transcriptional antiterminator rna.	we show that ribosomal protein s1 specifically binds the boxa transcriptional antiterminator rnas of bacteriophage lambda and the escherichia coli ribosomal rna operons. although s1 competes with the nusb-s10 antitermination complex for binding to boxa, it does not affect antitermination by the lambda n protein in vitro, and its role, if any, in rrna synthesis is still unknown.	1998	9555913
the helicobacter felis ftsh gene encoding an atp-dependent metalloprotease can replace the escherichia coli homologue for growth and phage lambda lysogenization.	cloning and sequencing of an approximately 6.0-kb chromosomal dna fragment from helicobacter felis revealed five complete open reading frames. the deduced amino acid sequence of one orf exhibited sequence similarity to the ftsh protein, an atp-dependent metalloprotease, from various bacterial species. the encoded protein consists of 638 amino acid residues with a molecular mass of 70.2 kda. the hydropathy profile of the ftsh protein predicted two n-terminal transmembrane regions that were confir ...	1998	9560419
[dna inside bacteriophage lambda forms a z-form].	the site of the transition regions between the b- and z-forms of the dna duplex (b-z junction) may serve as marker of the existence of z-dna in situ. the structure of (dc-dg)10 insert in the bacteriophage lambda gt10 has been studied in situ by modification of b-z junction with o-beta-diethylaminoethylhydroxylamine (oha). the latter is an analogue of hydroxylamine possessing specificity with respect to unpaired cytidine. this modification inhibited the process of restriction at bamhi site adjace ...	1998	9567177
induction of mutations by 2-acetylaminofluorene in laci transgenic b6c3f1 mouse liver.	mutations induced in liver cells by the hepatocarcinogen 2-acetylaminofluorene (2-aaf) were characterized after i.p. administration on 4 consecutive days at 100 mg/kg per injection in male b6c3f1 big blue transgenic mice that harbored the escherichia coli laci reporter gene. animals were sacrificed at 5, 10 or 60 weeks following the last injection, livers removed and dna packaged in vitro into bacteriophage lambda particles. the bacteriophage were assayed for laci function by plating on e. coli ...	1998	9568591
nmr structure of the bacteriophage lambda n peptide/boxb rna complex: recognition of a gnra fold by an arginine-rich motif.	the structure of the complex formed by the arginine-rich motif of the transcriptional antitermination protein n of phage lambda and boxb rna was determined by heteronuclear magnetic resonance spectroscopy. a bent alpha helix in n recognizes primarily the shape and negatively charged surface of the boxb hairpin through multiple hydrophobic and ionic interactions. the gaaga boxb loop forms a gnra fold, previously described for tetraloops, which is essential for n binding. the fourth nucleotide of ...	1998	9568720
the lambda holin accumulates beyond the lethal triggering concentration under hyperexpression conditions.	most bacteriophages terminate infection by creating lesions in the cytoplasmic membrane, which not only cause immediate cell death but also allow escape of a phage-encoded endolysin. destruction of the peptidoglycan and cell lysis follows very rapidly, allowing efficient release of the progeny virions. these membrane lesions are formed by a small integral membrane protein called a holin. holins have highly charged carboxyl-termini that are thought to have two transmembrane alpha-helical domains. ...	1998	9572396
single-chain lambda cro repressors confirm high intrinsic dimer-dna affinity.	the overall affinity of the bacteriophage lambda cro repressor for its operator dna site is limited by dimer dissociation at submicromolar concentrations. since cro dimer-operator complexes form at nanomolar concentrations of cro subunits where free dimers are rare, these dimers must bind with compensating high affinities. previous studies of the covalent dimer cro v55c suggest little change in dna binding affinity even though the dimeric species is quantitatively populated; this is an apparent ...	1998	9572862
metalloadsorption by escherichia coli cells displaying yeast and mammalian metallothioneins anchored to the outer membrane protein lamb.	yeast (cup1) and mammalian (hmt-1a) metallothioneins (mts) have been efficiently expressed in escherichia coli as fusions to the outer membrane protein lamb. a 65-amino-acid sequence from the cup1 protein of saccharomyces cerevisiae (yeast [y] mt) was genetically inserted in permissive site 153 of the lamb sequence, which faces the outer medium. a second lamb fusion at position 153 was created with 66 amino acids recruited from the form of human (h) mt that is predominant in the adipose tissue, ...	1998	9573175
molecular mechanism of heat shock-provoked disassembly of the coliphage lambda replication complex.	we have found previously that, in contrast to the free o initiator protein of lambda phage or plasmid rapidly degraded by the escherichia coli clpp/clpx protease, the lambdao present in the replication complex (rc) is protected from proteolysis. however, in cells growing in a complete medium, a temperature shift from 30 to 43 degrees c resulted in the decay of the lambdao fraction, which indicated disassembly of rc. this process occurred due to heat shock induction of the groe operon, coding for ...	1998	9573201
computerized analysis of restriction fragment length polymorphism patterns: comparative evaluation of two commercial software packages.	two computerized restriction fragment length polymorphism pattern analysis systems, the bioimage system and the gelcompar system (molecular analyst fingerprinting plus in the united states), were compared. the two systems use different approaches to compare patterns from different gels. in gelcompar, a standard reference pattern in one gel is used to normalize subsequent gels containing lanes with the same reference pattern. in bioimage, the molecular sizes of the fragments are calculated from s ...	1998	9574697
characterization of the regulatory regions in the human desmoglein genes encoding the pemphigus foliaceous and pemphigus vulgaris antigens.	the adhesive proteins in the desmosome type of cell junction consist of two members of the cadherin superfamily, the desmogleins and desmocollins. both desmogleins and desmocollins occur as at least three different isoforms with various patterns of expression. the molecular mechanisms controlling the differential expression of the desmosomal cadherin isoforms are not yet known. we have begun an investigation of desmoglein gene expression by cloning and analysing the promoters of the human genes ...	1998	9405290
endonuclease v (nfi) mutant of escherichia coli k-12.	endonuclease v (deoxyinosine 3' endonuclease), the product of the nfi gene, has a specificity that encompasses dnas containing dimp, abasic sites, base mismatches, uracil, and even untreated single-stranded dna. to determine its importance in dna repair pathways, nfi insertion mutants and overproducers (strains bearing nfi plasmids) were constructed. the mutants displayed a twofold increase in spontaneous mutations for several markers and an increased sensitivity to killing by bleomycin and nitr ...	1998	9422591
characterization of a molecular clone of hiv type 2 infectious for macaca nemestrina.	a lambda phage clone containing a full-length hiv-2 provirus, designated hiv-2kr, was obtained from the genomic dna of molt4 clone 8 (molt4/8) lymphoblastic cells infected with the hiv-2pei2 strain. hiv-2kr is genetically distinct from known hiv-2 isolates, possessing both a unique deletion in the ltr promoter region, and a long rev reading frame. it is replication competent in vitro after transfection into molt4/8 cells, replicates in a variety of established human t lymphoblastic (molt-3, molt ...	1998	9453253
embryonic stem cell gene targeting using bacteriophage lambda vectors generated by phage-plasmid recombination.	targeted mutagenesis is an extremely useful experimental approach in molecular medicine, allowing the generation of specialized animals that are mutant for any gene of interest. currently the rate determining step in any gene targeting experiment is construction of the targeting vector (tv). in order to streamline gene targeting methods and avoid problems encountered with plasmid tvs, we describe the direct application of lambda phage in targeted mutagenesis. the recombination-proficient phage v ...	1998	9461458
involvement of boxa nucleotides in the formation of a stable ribonucleoprotein complex containing the bacteriophage lambda n protein.	the association of the transcriptional antitermination protein n of bacteriophage lambda with escherichia coli rna polymerase depends on nut site rna (boxa + boxb) in the nascent transcript and the host protein, nusa. this ribonucleoprotein complex can transcribe through rho-dependent and intrinsic termination sites located up to several hundred base pairs downstream of nut. for antitermination to occur farther downstream, this core antitermination complex must be stabilized by the host proteins ...	1998	9461609
microchip device for cell lysis, multiplex pcr amplification, and electrophoretic sizing.	the steps of cell lysis, multiplex pcr amplification, and electrophoretic analysis are executed sequentially on a monolithic microchip device. the entire microchip is thermally cycled to lyse cells and to amplify dna, and the products are then analyzed using a sieving medium for size separation and an intercalating dye for fluorescence detection. using a standard pcr protocol, a 500-base pair (bp) region of bacteriophage lambda dna and 154-, 264-, 346-, 410-, and 550-bp regions of e. coli genomi ...	1998	9463271
peptide nucleic acid-targeted mutagenesis of a chromosomal gene in mouse cells.	peptide nucleic acids (pnas) can bind to single-stranded dna by watson-crick base pairing and can form triple helices via hoogsteen bonding to dna/pna duplexes. a single dimeric pna molecule can form a clamp via both double- and triple-helix formation. we designed pnas to bind as clamps to a site in the supfg1 mutation reporter gene carried within a chromosomally integrated, recoverable lambda phage shuttle vector in mouse fibroblasts. the pnas were introduced into the cells via permeabilization ...	1998	9465026
escherichia coli nusa is required for efficient rna binding by phage hk022 nun protein.	the nun protein of phage hk022 is an rna binding protein of the arginine-rich motif family. nun binds the phage lambda boxb rna sequence (boxb) on nascent lambda transcripts and arrests transcription elongation. binding to boxb is inhibited by zn2+ and stimulated by the escherichia coli nusa protein. deletion of the nun c-terminal region enhances boxb binding and makes it independent of zn2+ and nusa. the c terminus of nun thus appears to interfere with the n-terminal rna binding motif. nusa rel ...	1998	9465052
the normal copy of the g0s19-3-associated, cpg island-containing, upstream sequence is downstream of g0s19-2/mip1alpha in association with a tre17 oncogene.	the g0s19-1/mip1alpha and g0s19-2/mip1alpha genes locate to human chromosomes 17q and encode similar copies of the beta-chemokine g0s19/mip1alpha. the g0s19-3 gene, present in 1 in 4 humans, is a 5' truncated version of g0s19-2; a cpg island-containing upstream sequence (cpg-us), rich in potential transcriptional activation motifs, replaces much of the first intron and the first exon. sequences hybridizing with the cpg-us sequence, normally exist in all human genomes. thus, it appears that there ...	1998	9468223
a physical map of the genome of ethanol fermentative bacterium zymomonas mobilis zm4 and localization of genes on the map.	a physical map of the zymomonas mobilis zm4 genome has been constructed from the results of reciprocal southern hybridization with pmei, paci, and noti-digested genomic dna fragments and linking cosmid clones. restriction enzyme-digested z. mobilis zm4 genome was electrophoresed with phage lambda dna concatemers as a size standard in a bio-rad chef-drii pulsed-field gel electrophoresis (pfge) system. the restriction enzyme pmei generated 15 fragments (3-625 kb), and paci produced 19 fragments (7 ...	1998	9469936
inci1 plasmid r64 encodes the arsr protein that alleviates type i restriction.	the host-controlled ecok restriction of unmodified phage lambda was five-fold alleviated in the wild-type escherichia coli strain k12 carrying the r64 plasmid of the incompatibility group i1. the relevant gene was mapped between the origin of vegetative replication (rep, oriv) and the tet(r) gene about 60 kbp downstream from the origin of transfer, orit. we cloned this gene inside the 613 bp long ecori-psti fragment and sequenced it. only one 351 bp long open reading frame (orf) starting at 124 ...	1998	9598970
genome organization of xestia c-nigrum granulovirus.	in order to characterize the genome organization of xestia c-nigrum granulovirus (xcgv), mapping of putative xcgv genes was performed by construction of lambda and m13 phage libraries followed by southern blot and nucleotide sequencing analyses. mapping of the lambda (32 clones covering the entire xcgv genome) and m13 (133 clones made by random cloning) phage library clones was carried out by hybridization of the labeled lambda phage clone dnas to 1) southern blotted xcgv genomic dna fragments c ...	1998	9608666
[cos-region of temperate coliphage n15].	the cohesive termini including the cos region (altogether 414 bp) of the dna of the temperate coliphage n15 are sequenced. the termini are complementary 12-nucleotide single-stranded 5'-extended dnas. the sequence of the left terminus is 5'-gggcggcgtccg-3', that of the right 5'cggacgccgccc-3'. ten nucleotides of the n15 termini are identical to those of phage lambda. the n15 and lambda sequences are notably homologous only within the 50 bp region from the left and right ends. phage n15 has a reg ...	1998	9611756
[novel site-specific endonucleases from brevibacterium species].	new site-specific endonucleases becai and becaii have been detected in brevibacterium species a. endonuclease becaii free from contaminating nonspecific endonucleases, exonucleases, and phosphatases was isolated by column chromatography on phosphocellulose, heparin sepharose, and dna cellulose. it recognizes and cleaves the 5'-gg decreases cc-3' sequence and is a true isoschizomer of haeiii restriction enzyme. the other restriction endonuclease, becai, cleaves ad2 dna at least by 2 sites but not ...	1998	9611761
incorporation of 1,2,4-triazole-3-alanine into a mutant of phage lambda lysozyme containing a single histidine.	the only histidine residue in the h31n-h137n double mutant of phage lambda lysozyme (lambdal), at position 48, was biosynthetically replaced by the analogue 1,2,4-triazole-3-alanine (taz), the basicity of which is 3 pka units lower. a histidine-auxotrophic strain was grown to stationary phase by histidine limitation in a synthetic medium, then taz was added on induction to produce a lysozyme with approximately 75% incorporation. the taz-containing enzyme precipitated selectively from the cytopla ...	1998	9613845
expression and mutational analysis of the baculovirus very late factor 1 (vlf-1) gene.	we have examined the expression and function of a gene, vlf-1, of autographa californica nuclear polyhedrosis virus that is known to encode a regulator of very late gene transcription. western blot analysis revealed that vlf-1 is expressed during the late phase of infection, primarily from 15 to 24 h postinfection. vlf-1 localized in the cell nucleus and was also present in the nucleocapsids of virus particles. mapping of vlf-1 mrna by primer extension showed that transcription initiates at a ta ...	1998	9614871
biochemical and immunological characterization of rice homologues of the human immunodeficiency virus-1 tat binding protein and subunit 4 of human 26s proteasome subunits.	previously, we isolated two cdna clones, tbpos-1 and tbpos-2, encoding putative atpases that are the rice homologues of human immunodeficiency virus-1 (hiv-1) tat binding protein-1 and subunit 4 of human 26s proteasome. in order to determine the rna-dependent atpase activity of these putative proteins, the subclones from these cdna clones were expressed in escherichia coli as fusion proteins with maltose-binding protein. the recombinant proteins stimulated atp hydrolysis in the presence of poly( ...	1998	9617816
random inheritance of the replication complex by one of two daughter lambda plasmid copies after a replication round in escherichia coli.	there are two pathways for replication of plasmids derived from bacteriophage lambda (so-called lambda plasmids) in escherichia coli. one pathway is based on the assembly of the new replication complex at ori lambda, and the second requires activity of the replication complex inherited by one of two daughter plasmid copies after each replication round. although these two replication pathways proceed at the same time in the host cell, we previously found conditions for specific elimination of the ...	1998	9618264
a comprehensive panel of near-full-length clones and reference sequences for non-subtype b isolates of human immunodeficiency virus type 1.	non-subtype b viruses cause the vast majority of new human immunodeficiency virus type 1 (hiv-1) infections worldwide and are thus the major focus of international vaccine efforts. although their geographic dissemination is carefully monitored, their immunogenic and biological properties remain largely unknown, in part because well-characterized virological reference reagents are lacking. in particular, full-length clones and sequences are rare, since subtype classification is frequently based o ...	1998	9621027
cloning of equine interleukin 1 alpha and equine interleukin 1 beta and determination of their full-length cdna sequences.	to clone equine interleukin 1 alpha (il-1 alpha) and equine interleukin 1 beta (il-1 beta) and determine their full-length cdna sequences.	1998	9622738
4-chloro-o-phenylenediamine: a 26-week oral (in feed) mutagenicity study in big blue mice.	4-chloro-o-phenylenediamine (4-c-o-pda) is a liver carcinogen in mice and was found to be weakly mutagenic in the liver of female big blue mice after short term treatment. in the present study the test compound was given subchronically in the diet for 26 weeks at doses of 0, 5000 and 10,000 ppm. the corresponding average test substance intake was 2166 mg kg-1 day-1 (males: 1794 mg kg-1 day-1; females: 2539 mg kg-1 day-1) and 4610 mg kg-1 day-1 (males: 3926 mg kg-1 day-1; females 5925 mg kg-1 day ...	1998	9630584
structure and sequence of human m/nei (monocyte/neutrophil elastase inhibitor), an ov-serpin family gene.	human monocyte/neutrophil elastase inhibitor (m/nei) is a proteinase inhibitor that regulates the activity of the neutrophil proteases: elastase, cathepsin g and proteinase-3. evidence indicates that m/nei belongs to the ov-serpin family (ovalbumin-related serpins), functionally diverse proteins with shared structural features. recombinant lambda phage clones were isolated that encompass the full-length m/nei gene plus upstream and downstream regions. the gene, 9.5kb long, consists of 7 exons an ...	1998	9630619
mutations affecting cooperative dna binding of phage hk022 ci repressor.	cooperative protein-dna interactions play critical roles in gene regulation in all organisms. among the best-studied cooperative interactions is that of phage lambda repressor, which binds cooperatively to two adjacent operators. similar cooperative interactions are also shown by several other lambdoid phage repressors, including hk022 ci repressor, which we study here. this protein has a much higher degree of cooperativity than seen with lambda repressor, and previous evidence has suggested tha ...	1998	9636698
different pathways for protein degradation by the ftsh/hflkc membrane-embedded protease complex: an implication from the interference by a mutant form of a new substrate protein, ycca.	escherichia coli ftsh (hflb) is a membrane-bound and atp-dependent zinc-metalloproteinase, which forms a complex with a pair of periplasmically exposed membrane proteins, hflk and hflc. it is the protease that degrades uncomplexed forms of the secy subunit of protein translocase. here, we characterized a new class of secy-stabilizing mutation on the e. coli chromosome. the mutation (ycca11) is an internal deletion within a gene (ycca) known as an open reading frame for a hydrophobic protein with ...	1998	9636708
recognition of core-type dna sites by lambda integrase.	escherichia coli phage lambda integrase (int) is a 40 kilodalton, 356 amino acid residue protein, which belongs to the lambda int family of site-specific recombinases. the amino-terminal domain (residues 1 to 64) of int binds to "arm-type" dna sites, distant from the sites of dna cleavage. the carboxy-terminal fragment, termed c65 (residues 65 to 356), binds "core-type" dna sites and catalyzes cleavage and ligation at these sites. it has been further divided into two smaller domains, encompassin ...	1998	9641975
replication strand preference for deletions associated with dna palindromes.	we have isolated and sequenced a set of deletions stimulated by dna palindromes in escherichia coli. all of the deletions are asymmetric with respect to the parental sequence and have occurred at short direct repeats. this is consistent with deletion by strand slippage during dna replication. the orientation of the asymmetry in such deletion products is diagnostic of the direction of the strand slippage event. it is therefore also diagnostic of its occurrence on the leading or lagging strand of ...	1998	9643540
the phage lambda terminase enzyme: 1. reconstitution of the holoenzyme from the individual subunits enhances the thermal stability of the small subunit.	the terminase enzyme from bacteriophage lambda is a hetero-trimeric complex composed of the viral gpa and gpnu1 proteins (gpa1.gpnu1(2)) and is responsible for packaging a single genome within the viral capsid. current expression systems for these proteins require thermal induction which may be responsible for the formation of insoluble aggregates observed in e. coli. we report the re-cloning of the terminase subunits into vectors which allow low temperature induction. while this has resulted in ...	1998	9644594
the phage lambda terminase enzyme: 2. refolding of the gpnu1 subunit from the detergent-denatured and guanidinium hydrochloride-denatured state yields different oligomerization states and altered protein stabilities.	the terminase enzyme from bacteriophage lambda is responsible for packaging a single genome within the viral capsid. gold and co-workers have developed a scheme for the solubilization of the small terminase subunit (gpnu1) from inclusion bodies using the strong detergent sarkosyl and purification of the protein to homogeneity (gpnu1srk) (parris et al., j biol chem 1994;269:13564-13574). we have developed a similar purification scheme except that guanidinium hydrochloride was used to denature the ...	1998	9644595
lambda bar minigene-mediated inhibition of protein synthesis involves accumulation of peptidyl-trna and starvation for trna.	expression of the bacteriophage lambda two-codon, aug aua, bari minigene (bar+) leads to the arrest of protein synthesis in cells defective in peptidyl-trna hydrolase (pth). it has been hypothesized that translation of the bar+ transcript provokes premature release and accumulation of peptidyl-trna (p-trna). inhibition of protein synthesis would then result from either starvation of sequestered trna or from toxicity of accumulated p-trna. to test this hypothesis and to investigate the cause of a ...	1998	9649445
production of a new dna vehicle for gene transfer using site-specific recombination.	supercoiled dna molecules, minicircles, were produced by in vivo site-specific recombination. they contained exclusively the desired excisable fragment. recombination was driven by bacteriophage lambda integrase from a plasmid substrate containing the attp and attb recombination sites in the same orientation. conditions for minicircle production within the lysogen escherichia coli d1210hp were optimised. up to 1.5 mg minicircles could be produced per litre bacterial culture, and the remaining, u ...	1998	9650254
use of lambda phage dna as a hybrid internal control in a pcr-enzyme immunoassay to detect chlamydia pneumoniae.	an inherent problem in the diagnostic pcr assay is the presence of ill-defined inhibitors of amplification which may cause false-negative results. addition of an amplifiable fragment of foreign dna in the pcr to serve as a hybrid internal control (hic) would allow for a simple way to identify specimens containing inhibitors. two oligonucleotide hybrid primers were synthesized to contain nucleic acid sequences of the chlamydia pneumoniae 16s rrna primers in a position flanking two primers that ta ...	1998	9650936
termination of packaging of the bacteriophage lambda chromosome: cosq is required for nicking the bottom strand of cosn.	termination of packaging of the lambda chromosome involves completion of translocation of the dna into the head shell, and conversion of the translocation complex into a cleavage complex. the cleavage reaction introduces staggered nicks into the downstream cosn to generate the right cohesive end of the chromosome. cosq, a site adjacent to cosn, was found to be required for nicking the bottom strand of cosn; bottom strand nicking was also sequence-specific for bps at the nick site. nicking of the ...	1998	9653028
refined structure of cro repressor protein from bacteriophage lambda suggests both flexibility and plasticity.	the structure of the cro repressor protein from phage lambda has been refined to a crystallographic r-value of 19.3% at 2.3 a resolution. the re fined model supports the structure as originally described in 1981 and provides a basis for comparison with the cro-operator complex described in the accompanying paper. changes in structure seen in different crystal forms and modifications of cro suggest that the individual subunits are somewhat plastic in nature. in addition, the dimer of cro suggests ...	1998	9653036
crystal structure of lambda-cro bound to a consensus operator at 3.0 a resolution.	the structure of the cro protein from bacteriophage lambda in complex with a 19 base-pair dna duplex that includes the 17 base-pair consensus operator has been determined at 3.0 a resolution. the structure confirms the large changes in the protein and dna seen previously in a crystallographically distinct low-resolution structure of the complex and, for the first time, reveals the detailed interactions between the side-chains of the protein and the base-pairs of the operator. relative to the cry ...	1998	9653037
independent ligand-induced folding of the rna-binding domain and two functionally distinct antitermination regions in the phage lambda n protein.	the transcriptional antitermination protein n of bacteriophage lambda binds the boxb component of the rna enhancer nut (boxa + boxb) and the e. coli elongation factor nusa. efficient antitermination by n requires an rna-binding domain (amino acids 1-22) and two activating regions for antitermination: a newly identified nusa-binding region (amino acids 34-47) that suppresses nusa's enhancement of termination, and a carboxy-terminal region (amino acids 73-107) that interacts directly with rna poly ...	1998	9659923
polyadenylation of oop rna in the regulation of bacteriophage lambda development.	we have shown that escherichia coli pcnb mutants are lysogenized by bacteriophage lambda with lower efficiency as compared to the pcnb+ strains. our genetic analysis revealed that expression of the lambda cii gene is decreased in the pcnb mutants. however, using various lacz fusions we demonstrated that neither activities of pl and pr promoters nor transcription termination at tr1 were significantly impaired in the pcnb- host. on the other hand, we found that oop rna, an antisense rna for cii ex ...	1998	9661664
antibody screening of bacteriophage lambda gt-11 dna expression libraries.		1998	9664400
large- and small-scale preparation of bacteriophage lambda lysate and dna.		1998	9668973
regulation of replication of lambda phage and lambda plasmid dnas at low temperature.	it was previously demonstrated that while lysogenic development of bacteriophage lambda in escherichia coli proceeds normally at low temperature (20-25 degrees c), lytic development is blocked under these conditions owing to the increased stability of the phage cii protein. this effect was proposed to be responsible for the increased stimulation of the pe promoter, which interferes with expression of the replication genes, leading to inhibition of phage dna synthesis. here we demonstrate that th ...	1998	9669331
solution structure of the antitermination protein nusb of escherichia coli: a novel all-helical fold for an rna-binding protein.	the nusb protein of escherichia coli is involved in the regulation of rrna biosynthesis by transcriptional antitermination. in cooperation with several other proteins, it binds to a dodecamer motif designated rrn boxa on the nascent rrna. the antitermination proteins of e.coli are recruited in the replication cycle of bacteriophage lambda, where they play an important role in switching from the lysogenic to the lytic cycle. multidimensional heteronuclear nmr experiments were performed with recom ...	1998	9670024
lambda repressor n-terminal dna-binding domain as an assay for protein transmembrane segment interactions in vivo.	to understand the determinants of membrane protein interactions, we have developed an in vivo genetic assay system for detecting homodimerization of transmembrane (tm) segments from integral membrane proteins. our approach is to generate gene fusions between potentially dimerizing tm segments and a cytoplasmic dna-binding protein that lacks its intrinsic dimerization domain. this genetic approach allows us to screen and distinguish among known dimerizing domains and weakly dimerizing mutants, as ...	1998	9671551
characterization of the thermal stress response of campylobacter jejuni.	campylobacter jejuni, a microaerophilic, gram-negative bacterium, is a common cause of gastrointestinal disease in humans. heat shock proteins are a group of highly conserved, coregulated proteins that play important roles in enabling organisms to cope with physiological stresses. the primary aim of this study was to characterize the heat shock response of c. jejuni. twenty-four proteins were preferentially synthesized by c. jejuni immediately following heat shock. upon immunoscreening of escher ...	1998	9673247
molecular characterization of mouse pneumocystis carinii surface glycoprotein a.	since the mouse offers an easily manipulated experimental animal model for the study of the immunopathogenesis of pneumonia caused by the opportunist pneumocystis carinii, we cloned and characterized cdnas encoding an abundant, immunogenic surface antigen termed glycoprotein a (gpa) from mouse p. carinii. a cdna library was constructed in bacteriophage lambda gt11 from p. carinii-infected mouse lung poly(a+) rna. using a nucleic acid probe derived from a conserved region of the mouse p. carinii ...	1998	9679195
regulation of rat glutathione s-transferase a5 by cancer chemopreventive agents: mechanisms of inducible resistance to aflatoxin b1.	the rat can be protected against aflatoxin b1 (afb1) hepatocarcinogenesis by being fed on a diet containing the synthetic antioxidant ethoxyquin. evidence suggests that chemoprotection against afb1 is due to increased detoxification of the mycotoxin by one or more inducible drug-metabolising enzymes. the glutathione s-transferase (gst) isoenzymes in rat liver that contribute to ethoxyquin-induced chemoprotection against afb1 have been identified by protein purification. this approach resulted in ...	1998	9679543
functional and genetic analysis of regulatory regions of coliphage h-19b: location of shiga-like toxin and lysis genes suggest a role for phage functions in toxin release.	analysis of the dna sequence of a 17 kb region of the coli lambdoid phage h-19b genome located the genes encoding shiga-like toxin i (stx-i) downstream of the gene encoding the analogue of the phage lambda q transcription activator with its site of action, qut at the associated pr' late promoter, and upstream of the analogues of lambda genes encoding lysis functions. functional studies, including measurement of the effect of h-19b q action on levels of stx expressed from an h-19b prophage, show ...	1998	9680214