Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| fine-structure analysis of the p7 plasmid partition site. | the par region of bacteriophage p7 is responsible for active partition of the p7 plasmid prophage into daughter cells. the cis-acting partition site was defined precisely as a 75-bp sequence that was necessary and sufficient to promote correct segregation of an unstable vector plasmid when the two p7 partition proteins, para and parb, were supplied in trans. roughly the same region was necessary to exert partition-mediated incompatibility. the minimal site contains an integration host factor (ih ... | 1993 | 8501048 |
| independent control of immunoglobulin switch recombination at individual switch regions evidenced through cre-loxp-mediated gene targeting. | we have employed a method based on the cre-loxp recombination system of bacteriophage p1 to generate a mouse strain in which the jh segments and the intron enhancer in the igh locus are deleted. by analysis of immunoglobulin isotype switch recombination in heterozygous mutant b cells activated by lipopolysaccharide plus interleukin-4, we show that, on the mutant chromosome, switch recombination at the mu gene switch region is strongly suppressed, whereas the switch region of the gamma 1 gene is ... | 1993 | 8513499 |
| tko'ed: lox, stock and barrel. | the generation of panels of mutant mice by homologous recombination has greatly increased the ability to assess the function of particular gene products in vivo. the ability to control the developmental stage, the tissue and the nature of the mutation would be an important innovation. a recent report demonstrates that the conservative site-specific recombination of bacteriophage p1, namely cre-lox, can be used successfully in combination with homologous recombination to generate temporal- and ce ... | 1994 | 7840765 |
| towards cloning the familial breast-ovarian cancer gene on chromosome 17. | the past year has seen a great deal of excitement in the field of breast cancer genetics. since linkage of the familial breast-ovarian cancer gene (brca1) to chromosome 17, the critical region has been narrowed to 1.0-1.5 mb by recombination studies, a detailed physical map has been constructed and much of the region has been cloned in yeast artificial chromosome, bacteriophage p1 and cosmid vectors. the focus now lies on identifying the genes housed within the brca1 region and scanning them for ... | 1994 | 7919922 |
| purification and dna-binding activity of the paca subunit of the bacteriophage p1 pacase enzyme. | the bacteriophage p1 packaging site (pac) cleavage enzyme (pacase) consists of two phage encoded proteins, paca and pacb. both proteins are necessary for the recognition and cleavage of pac and for subsequent packaging of cleaved dna into phage particles. we have purified paca to homogeneity from a bacterial strain that overproduces the protein. purified paca complements an escherichia coli extract containing the pacb protein for dna cleavage at the pac site and recognizes and binds to methylate ... | 1994 | 7932754 |
| faithful cleavage of the p1 packaging site (pac) requires two phage proteins, paca and pacb, and two escherichia coli proteins, ihf and hu. | the paca and pacb subunits of the bacteriophage p1 dna packaging enzyme (pacase) are necessary for cleavage of the phage packaging site (pac). in the accompanying paper, we show that the paca subunit of the enzyme specifically binds to pac in the absence of pacb, but requires factors present in an escherichia coli extract to do so. we show here that either of two e. coli dna binding proteins, integration host factor (ihf) or hu, can replace this extract and promote the binding of paca to pac. ih ... | 1994 | 7932755 |
| c1 repressor-mediated dna looping is involved in c1 autoregulation of bacteriophage p1. | c1 repressor is required to repress the lytic functions of a p1 prophage in vivo. transcription of the c1 gene is autoregulated via the c1-controlled operator op99a,b which overlaps the promoter of the c1 gene. it is negatively affected by lxc corepressor and the dna region upstream of c1, which contains the additional operators op99c, d, and e. we have explored these effects by constructing a set of lacz reporter plasmids with op99a,b and varying parts of the upstream dna region. transcription ... | 1994 | 7989363 |
| mutations affecting a regulated, membrane-associated esterase in salmonella typhimurium lt2. | mutations at the apea locus in salmonella typhimurium lead to loss of a soluble enzyme ("protease i") that hydrolyzes the chromogenic endoprotease substrate n-acetyl phenylalanine beta-naphthyl ester. we have isolated pseudorevertants of s. typhimurium apea mutations that have regained the ability to hydrolyze this compound. these pseudorevertants contain mutations (aper) that lead to overproduction of a membrane-bound esterase different from protease i. the aper locus is phage p1 cotransducible ... | 1994 | 8028584 |
| genome structure and evolution in drosophila: applications of the framework p1 map. | physical maps showing the relative locations of cloned dna fragments in the genome are important resources for research in molecular genetics, genome analysis, and evolutionary biology. in addition to affording a common frame of reference for organizing diverse types of genetic data, physical maps also provide ready access to clones containing dna sequences from any defined region of the genome. in this paper, we present a physical map of the genome of drosophila melanogaster based on in situ hy ... | 1994 | 8041703 |
| cloning of the region between hla-dmb and lmp2 in the human major histocompatibility complex. | the human mhc is one of the most extensively mapped regions of the human genome. almost all of the class ii region of the mhc has already been cloned in cosmids but a gap remained between the dmb and lmp2 genes. previously, screening of several complete cosmid libraries had failed to bridge this gap, which may contain novel antigen processing or presentation genes. we constructed cosmid libraries from two different sources in order to clone the region: (a) a library with fourfold coverage made f ... | 1994 | 8045787 |
| second-site suppressors of the bacteriophage p1 virs mutant reveal the interdependence of the c4, icd, and ant genes in the p1 immi operon. | the immi operon of phage p1 contains the genes c4, icd, and ant, which are transcribed in that order from the same constitutive promoter, p51b. the gene c4 encodes an antisense rna which inhibits the synthesis of an antirepressor by acting on a target ant mrna. interaction depends on the complementarity of two pairs of short sequences encompassing virs+ and the ribosome-binding site involved in ant expression. accordingly, in a p1 virs mutant phage, antirepressor is synthesized constitutively. w ... | 1994 | 8051007 |
| characterization of the genomic structure, chromosomal location and promoter of human prostaglandin h synthase-2 gene. | prostaglandin h synthase (pghs) is the rate-limiting enzyme in the conversion of arachidonic acid to prostanoids. the human pghs has two isoforms. pghs-1 is a house keeping gene whereas pghs-2 is an inducible gene. we reported here the isolation of the entire pghs-2 gene and its 5'-flanking region from a human bacteriophage p1 genomic library. the gene containing 10 exons is 7.5 kb in length and located at chromosome 1. the transcriptional start site was mapped at 134 bases upstream from the atg ... | 1994 | 8074655 |
| cre recombinase-mediated site-specific recombination between plant chromosomes. | we report the use of the bacteriophage p1 cre-lox system for generating conservative site-specific recombination between tobacco chromosomes. two constructs, one containing a promoterless hygromycin-resistance gene preceded by a lox site (lox-hpt) and the other containing a cauliflower mosaic virus 35s promoter linked to a lox sequence and the cre coding region (35s-lox-cre), were introduced separately into tobacco plants. crosses between plants harboring either construct produced plants with th ... | 1994 | 8127869 |
| partition of nonreplicating dna by the par system of bacteriophage p1. | p1 plasmid encodes a cis-acting centromere analog, pars, and two par proteins that together stabilize plasmids by partitioning them to daughter bacteria. we infected immune bacteria with bacteriophage lambda into which pars had been inserted. the presence of p1 par proteins in the infected cells was found to delay the appearance of cells cured of the nonreplicating, extrachromosomal lambda-pars dna. this stabilization of lambda-pars, approximated in a computer simulation, demonstrates that activ ... | 1994 | 8132477 |
| a new bacteriophage p1-derived vector for the propagation of large human dna fragments. | we have designed a p1 vector (pcypac-1) for the introduction of recombinant dna into e. coli using electroporation procedures. the new cloning system, p1-derived artificial chromosomes (pacs), was used to establish an initial 15,000 clone library with an average insert size of 130-150 kilobase pairs (kb). no chimaerism has been observed in 34 clones, by fluorescence in situ hybridization. similarly, no insert instability has been observed after extended culturing, for 20 clones. we conclude that ... | 1994 | 8136839 |
| preparation and screening of an arrayed human genomic library generated with the p1 cloning system. | we describe here the construction and initial characterization of a 3-fold coverage genomic library of the human haploid genome that was prepared using the bacteriophage p1 cloning system. the cloned dna inserts were produced by size fractionation of a sau3ai partial digest of high molecular weight genomic dna isolated from primary cells of human foreskin fibroblasts. the inserts were cloned into the pad10sacbii vector and packaged in vitro into p1 phage. these were used to generate recombinant ... | 1994 | 8146166 |
| pid, a new member of the p1 bacteriophage group. | phage p1d produces particles of essentially uniform head size and differs from p1 in its range and tail length. the dimensions of phage p1 are reassessed. the p1 phage group shows signs of morphological evolution. | 1994 | 8149311 |
| glutathione s-transferase-sspa fusion binds to e. coli rna polymerase and complements delta sspa mutation allowing phage p1 replication. | bacteriophage p1 is unable to form plaques on e. coli hosts lacking a functional sspa gene. however, sspa mutants can be infected by p1, resulting in the synthesis of p1 early gene products and accumulation of p1 dna, but without p1 late gene product formation or host lysis. overexpression of the stringent starvation protein (sspa) as a glutathione-s-transferase fusion results in complementation of the sspa mutation and production of viable viral particles as in sspa+ strains. this suggests that ... | 1994 | 8198564 |
| cin-mediated recombination at secondary crossover sites on the escherichia coli chromosome. | the cin recombinase is known to mediate dna inversion between two wild-type cix sites flanking genetic determinants for the host range of bacteriophage p1. cin can also act with low frequency at secondary (or quasi) sites (designated cixq) that have lower homology to either wild-type site. an inversion tester sequence able to reveal novel operon fusions was integrated into the escherichia coli chromosome, and the cin recombinase was provided in trans. among a total of 13 cin-mediated inversions ... | 1995 | 7868587 |
| intra-chromosomal rearrangements generated by cre-lox site-specific recombination. | chromosomal rearrangements are useful genetic and breeding tools but are often difficult to detect and characterize. to more easily identify and define chromosome deletions and inversions, we have used the bacteriophage p1 cre-lox site-specific recombination system to generate these events in plants. this involves three steps: (i) the introduction of two lox sites into one locus in a plant genome, including one site within a modified ds transposon; (ii) ac transposase-mediated transposition of t ... | 1995 | 7885845 |
| the rpoe gene encoding the sigma e (sigma 24) heat shock sigma factor of escherichia coli. | previous work has established that the transcription factor sigma e (sigma 24) is necessary for maintaining the induction of the heat shock response of escherichia coli at high temperatures. we have identified the gene encoding sigma e using a genetic screen designed to isolate trans-acting mutations that abolish expression from either htra or rpohp3, two promoters recognized uniquely by sigma e-containing rna polymerase. such a screen was achieved by transducing strains carrying a single copy o ... | 1995 | 7889935 |
| techniques in mammalian genome mapping. | increasing emphasis is being given to genomic cloning using escherichia coli vectors of intermediate insert capacity, such as bacteriophage p1, p1-derived artificial chromosomes and the f factor based bacterial artificial chromosomes. these vectors are being used in addition to yeast artifical chromosomes (yacs) in recognition of the difficulties encountered with yac stability and with handling of yac dnas (problems that will not easily be overcome). nonetheless, yacs remain the most practical c ... | 1995 | 7894081 |
| gene structure and chromosomal localization of the human hsd11k gene encoding the kidney (type 2) isozyme of 11 beta-hydroxysteroid dehydrogenase. | 11 beta-hydroxysteroid dehydrogenase (11 beta hsd) converts glucocorticoids to inactive products and is thus thought to confer specificity for aldosterone on the type i mineralocorticoid receptor in the kidney. recent studies indicate the presence of at least two isozymes of 11 beta hsd. in vitro, the nad(+)-dependent kidney (type 2) isozyme catalyzes 11 beta-dehydrogenase but not reductase reactions, whereas the nadp(+)-dependent liver (type 1) isozyme catalyzes both reactions. we have now char ... | 1995 | 8530071 |
| analysis of the human gene encoding the kidney isozyme of 11 beta-hydroxysteroid dehydrogenase. | 11 beta-hydroxysteroid dehydrogenase (11 beta-hsd) catalyzes the conversion of cortisol to cortisone. this activity may be deficient in the syndrome of apparent mineralocorticoid excess (ame). 11 beta-hsd l (type i), isolated from liver, is widely expressed and utilizes nadp+ as a cofactor. the gene for 11 beta-hsd l was found to be normal in patients of ame. a second isoform, 11 beta-hsd k (type ii), isolated from kidney, is more tissue specific in expression and utilizes nad+ as a cofactor. th ... | 1995 | 8547172 |
| efficient gene activation in mammalian cells by using recombinant adenovirus expressing site-specific cre recombinase. | a recombinant adenovirus (ad) expressing cre recombinase derived from bacteriophage p1 was constructed. to assay the cre activity in mammalian cells, another recombinant ad bearing an on/off-switching reporter unit, where a lacz-expression unit can be activated by the cre-mediated excisional deletion of an interposed stuffer dna, was also constructed. co-infection experiments together with the cre-expressing and the reporter recombinant ads showed that the cre-mediated switching of gene expressi ... | 1995 | 7479022 |
| positional cloning of the nude locus: genetic, physical, and transcription maps of the region and mutations in the mouse and rat. | mutations in the nude locus in mice and rats produce the pleiotropic phenotype of hairlessness and athymia, resulting in severely compromised immune system. to identify the causative gene, we utilized modern tools and techniques of positional cloning. specifically, spanning the region in which the nude locus resides, we constructed a genetic map of polymorphic markers, a physical map of yeast artificial chromosomes and bacteriophage p1 clones, and a transcription map of genes obtained by direct ... | 1995 | 7490093 |
| efficient regulation of gene expression by adenovirus vector-mediated delivery of the cre recombinase. | we have constructed an e1-defective adenovirus (ad) vector designated adcag-cre containing the cre recombinase gene derived from bacteriophage p1 under control of the cytomegalovirus immediate early enhancer-chicken beta-actin hybrid (cag) promoter. we examined the cre-loxp-based recombination by this ad vector in c2c12 cells bearing a reporter gene construct cag-cat-z, which directs expression of the e. coli lacz gene upon cre-mediated excision of the cat gene located between the cag promoter a ... | 1995 | 7503713 |
| dna supercoiling in a thermotolerant mutant of escherichia coli. | a spontaneously occurring, nalidixic acid-resistant (nalr), thermotolerant (t/r) mutant of escherichia coli was isolated. bacteriophage p1-mediated transduction showed that nalr mapped at or near gyr a, one of the two genes encoding dna gyrase. expression of gyra+ from a plasmid rendered the mutant sensitive to nalidixic acid and to high temperature, the result expected for alleles mapping in gyra. plasmid linking number measurements, made with dna from cells grown at 37 degrees c or shifted to ... | 1995 | 7565605 |
| site-specific recombination mediated by an adenovirus vector expressing the cre recombinase protein: a molecular switch for control of gene expression. | we have constructed replication-defective human adenovirus (ad) type 5 vectors containing the gene for the cre recombinase from bacteriophage p1 under control of the human cytomegalovirus immediate-early promoter (adcre). expression of the protein was detected in replication-permissive (293) and in nonpermissive (mrc5) cell lines, and its biochemical activity was demonstrated in a cell-free recombination assay using a plasmid containing two loxp sites. to study cre-mediated recombination in an i ... | 1995 | 7609024 |
| cre-mediated site-specific translocation between nonhomologous mouse chromosomes. | chromosome rearrangements, such as large deletions, inversions, or translocations, mediate migration of large dna segments within or between chromosomes, which can have major effects on cellular genetic control. a method for chromosome manipulation would be very useful for studying the consequences of large-scale dna rearrangements in mammalian cells or animals. with the use of the cre-loxp recombination system of bacteriophage p1, we induced a site-specific translocation between the dek gene on ... | 1995 | 7638200 |
| transduction, restriction and recombination patterns in escherichia coli. | chromosomal dna from several escherichia coli reference (ecor) strains was transduced by bacteriophage p1 into e. coli strain k12 w3110 trpa33. recombination patterns of the transductants were determined by restriction fragment length polymorphism over a 40-kb region centering on a single marker (trpa+) in the tryptophan operon. these experiments demonstrate that transduction between different strains of e. coli can result in recombinational replacements that are small in comparison to the entra ... | 1995 | 7705636 |
| atp hydrolysis is required for dna cleavage by ecopi restriction enzyme. | the type iii restriction endonuclease ecopi, coded by bacteriophage p1, cleaves unmodified dna in the presence of atp and magnesium ions. we show that purified ecopi restriction enzyme fails to cleave dna in the presence of non-hydrolyzable atp analogs. more importantly, this study demonstrates that ecopi restriction enzyme has an inherent atpase activity, and atp hydrolysis is necessary for dna cleavage. furthermore, we show that the progress curve of the reaction with ecopi restriction enzyme ... | 1995 | 7723013 |
| site-specific recombination in the replication terminus region of escherichia coli: functional replacement of dif. | the replication terminus region of the escherichia coli chromosome encodes a locus, dif, that is required for normal chromosome segregation at cell division. dif is a substrate for site-specific recombination catalysed by the related chromosomally encoded recombinases xerc and xerd. it has been proposed that this recombination converts chromosome multimers formed by homologous recombination back to monomers in order that they can be segregated prior to cell division. strains mutant in dif, xerc ... | 1995 | 7729430 |
| partition of p1 plasmids in escherichia coli mukb chromosomal partition mutants. | the partition system of the low-copy-number plasmid/prophage of bacteriophage p1 encodes two proteins, para and parb, and contains a dna site called pars. parb and the escherichia coli protein ihf bind to pars to form the partition complex, in which pars is wrapped around parb and ihf in a precise three-dimensional conformation. partition can be thought of as a positioning reaction; the plasmid-encoded components ensure that at least one copy of the plasmid is positioned within each new daughter ... | 1995 | 7730268 |
| site-specific integration of dna into wild-type and mutant lox sites placed in the plant genome. | the bacteriophage p1 cre-lox site-specific recombination system has been used to integrate dna specifically at lox sites previously placed in the tobacco genome. as integrated molecules flanked by wild-type lox sites can readily excise in the presence of cre recombinase, screening for mutant lox sites that can resist excisional recombination was performed. in gene integration experiments, wild-type and mutant lox sites were used in conjunction with two strategies for abolishing post-integration ... | 1995 | 7742860 |
| physical mapping, cloning, and identification of genes within a 500-kb region containing brca1. | brca1 is a breast/ovarian cancer susceptibility gene on human chromosome 17q21. we describe a complete and detailed physical map of a 500-kb region of genomic dna containing the brca1 gene and the partial cloning in phage p1 artificial chromosomes. approximately 70 exons were isolated from this region, 11 of which were components of the brca1 gene. analysis of the other exons revealed a rho-related g protein and the interferon-induced leucine-zipper protein ifp-35. | 1995 | 7753812 |
| headful packaging revisited: the packaging of more than one dna molecule into a bacteriophage p1 head. | like a variety of other bacteriophages, such as t4 and p22, bacteriophage p1 packages dna by a "headful" mechanism in which the capacity of the viral capsid determines the size of the single dna molecule that is packaged. because of the long-standing and general acceptance of this packaging mechanism, we were surprised to discover that some of our observations, using the in vitro p1 packaging system, could be explained by the packaging of less than headful-sized (< 110 kb) dna molecules into a p ... | 1995 | 7776370 |
| the lytic replicon of bacteriophage p1 is controlled by an antisense rna. | the lytic replicon of phage p1 is used for dna replication during the lytic cycle. it comprises about 2% of the p1 genome and contains the p1 c1 repressor-controlled operator-promoter element op53.p53 and the kila and the repl genes, in that order. transcription of the lytic replicon of p53 and synthesis of the product of repl, but not kila, are required for replicon function. we have identified an additional promoter, termed p53as (antisense), at the 5'-end of the kila gene from which a 180 bas ... | 1995 | 7784198 |
| cloning, characterization, and chromosomal localization to 4p16 of the human gene (lrpap1) coding for the alpha 2-macroglobulin receptor-associated protein and structural comparison with the murine gene coding for the 44-kda heparin-binding protein. | we report the molecular cloning of the human gene (symbol lrpap1) coding for the alpha 2-macroglobulin receptor-associated protein (a2mrap), as well as the gene coding for the 44-kda heparin-binding protein (hbp-44), its murine counterpart. for both, genomic cosmid clones were isolated, and for the human gene a bacteriophage p1 clone containing the entire a2mrap gene was also retrieved. the genes were characterized after subcloning: in both species, the known coding part of the cdna is encoded b ... | 1995 | 7789983 |
| decrease in the linking number of plasmid dna in dnaa mutants of escherichia coli. | we made use of agarose gel electrophoresis in the presence of chloroquine to examine the linking number of plasmids in temperature-sensitive dnaa mutants, including dnaa5 and dnaa46 mutants. the linking number of dna prepared from dnaa mutants growing at 37 degrees c was lower than that from wild type cells yet there was no significant difference when cells were grown at 28 degrees c. complementation analysis with a plasmid containing the wild type dnaa gene and phage p1-mediated transduction co ... | 1996 | 8573119 |
| three functions of bacteriophage p1 involved in cell lysis. | amber and deletion mutants were used to assign functions in cell lysis to three late genes of bacteriophage p1. two of these genes, lyda and lydb of the dar operon, are 330 and 444 bp in length, respectively, with the stop codon of lyda overlapping the start codon of lydb. the third, gene 17, is 558 bp in length and is located in an otherwise uncharacterized operon. a search with the predicted amino acid sequence of lyda for secondary motifs revealed a holin protein-like structure. comparison of ... | 1996 | 8576044 |
| site-specific spontaneous deletions in three genome regions of a temperate streptococcus thermophilus phage. | site-specific spontaneous deletions were observed with high frequency in three regions of the genome of the temperate streptococcus thermophilus phage phi sfi21. deletion sizes were 750 bp (type 1), 2.7 kb (type 2), and 1 kb (type 3). combinations of types 1 and 3 and 2 and 3 were observed. the mutants grew lytically although with reduced burst sizes. type 2 mutants lost the capacity to lysogenize host cells. upon serial passage, the deletion mutants overgrew the wild-type phage. no direct or in ... | 1996 | 8623559 |
| targeted dna recombination in vivo using an adenovirus carrying the cre recombinase gene. | conditional gene expression and gene deletion are important experimental approaches for examining the functions of particular gene products in development and disease. the cre-loxp system from bacteriophage p1 has been used in transgenic animals to induce site-specific dna recombination leading to gene activation or deletion. to regulate the recombination in a spatiotemporally controlled manner, we constructed a recombinant adenoviral vector, adv/cre, that contained the cre recombinase gene unde ... | 1996 | 8632992 |
| an arrayed bacteriophage p1 genomic library of pneumocystis carinii. | we have constructed an arrayed, large insert, multiple coverage genomic library of pneumocystis carinii dna using the bacteriophage p1 cloning system. the library consists of approximately 4800 independent clones with an average insert size of approximately 55 kbp individually arrayed in 50 microtiter plates, and is readily screened on ten or fewer microtiter plate-sized filters using a high density colony replicating device. screening of the library for unique p. carinii sequences detected an a ... | 1996 | 8640187 |
| sequence scanning: a method for rapid sequence acquisition from large-fragment dna clones. | a strategy of "sequence scanning" is proposed for rapid acquisition of sequence from clones such as bacteriophage p1 clones, cosmids, or yeast artificial chromosomes. the approach makes use of a special vector, called lambdascan, that reliably yields subclones with inserts in the size range 8-12 kb. a number of subclones, typically 96 or 192, are chosen at random, and the ends of the inserts are sequenced using vector-specific primers. then long-range spectrum pcr is used to order and orient the ... | 1996 | 8643692 |
| the 21q22.1 sts marker, vn02 (est00541 cdna), is part of the 3' sequence of the human na+/myo-inositol cotransporter (slc5a3) gene. | the human osmoregulatory na+/myo-inositol cotransporter gene (slc5a3) was recently cloned and localized to the region of 21q22. fine mapping of this gene was accomplished by identifying yac clones that contain slc5a3 and utilizing known sts markers for 21q22.1 and 21q22.2 sub-bands that map to the positive yac clones. two bacteriophage p1 clones containing the slc5a3 gene gave a positive pcr product when screened with the 21q22.1 marker vn02, an expressed sequence tag (est00541). through dna seq ... | 1996 | 8646889 |
| phage display vectors for in vivo recombination of immunoglobulin heavy and light chain genes to make large combinatorial libraries. | new phage display vectors for in vivo recombination of immunoglobulin (ig) heavy (vh) and light (vl) chain variable genes, to make single-chain fv fragments (scfv), were constructed. the vh and vl genes of monoclonal antibody (mab) ep-5c7, which binds to both human e- and p-selectin, were cloned into a puc19-derived plasmid vector, pcw93, and a pacyc184-derived phagemid vector, pcw99, respectively. upon induction of cre recombinase (phage p1 recombinase), the vh and vl genes were efficiently rec ... | 1996 | 8654992 |
| rapid mapping of genomic p1 clones: the mouse l-isoaspartyl/d-aspartyl methyltransferase gene. | we report the mapping of the gene for the murine protein-l-isoaspartate (d-aspartate) o-methyltransferase (ec 2.1.1. 77) from a 129 mouse strain. this gene encodes an enzyme present in all tissues that can catalyze the first step of a repair reaction in which age-damaged proteins containing abnormal l-isoaspartyl (or d-aspartyl) residues can be converted to forms containing normal l-aspartyl residues. we first mapped the restriction sites from a genomic p1 clone using a rapid method generally ap ... | 1996 | 8661142 |
| adenovirus vector technology: an efficient method for constructing recombinant adenovirus and on/off switching of gene expression. | an efficient method of constructing recombinant adenoviruses (ad) has been established. the expression unit to be introduced into recombinant ad was first inserted into the unique swai site of the full-length ad genome cloned in a cassette cosmid. the cassette bearing the expression unit was then cotransfected to 293 cells together with the ad dna-terminal protein complex digested at several sites with ecot22i. the use of the parent ad dna-terminal protein complex instead of the deproteinized ad ... | 1996 | 8677800 |
| autoregulation of the plasmid addiction operon of bacteriophage p1. | the p1 plasmid addiction operon increases the apparent stability of a plasmid that carries it by killing plasmid-free (cured) segregants. the operon consists of a gene encoding an endotoxin responsible for death on curing (doc), preceded by a gene encoding a relatively unstable antidote that can prevent host death (phd). when the copy number of the operon was increased, expression of a lacz reporter fused to the promoter of the operon decreased, indicating that expression of the operon was stabi ... | 1996 | 8702525 |
| the escherichia coli k-12 gntp gene allows e. coli f-18 to occupy a distinct nutritional niche in the streptomycin-treated mouse large intestine. | escherichia coli f-18 is a human fecal isolate that makes type 1 fimbriae, encoded by the fim gene cluster, and is an excellent colonizer of the streptomycin-treated mouse intestine. e. coli f-18 fima::tet, lacking type 1 fimbriae, was constructed by bacteriophage p1 transduction of the fim region of the e. coli k-12 strain orn151, containing the tetracycline resistance gene from tn10 inserted in the fima gene, into e. coli f-18. e. coli f-18 fima::tet was found to occupy a distinct niche in the ... | 1996 | 8751890 |
| phage hk022 roi protein inhibits phage lytic growth in escherichia coli integration host factor mutants. | temperate coliphage hk022 requires integration host factor (ihf) for lytic growth. the determinant responsible for this requirement was identified as a new gene (roi) located between genes p and q. this gene encodes a dna-binding protein (roi) containing a helix-turn-helix motif. we have shown that roi binds a site within its own gene that is closely linked to an ihf binding site. by gel retardation experiments, we have found that ihf binding stabilizes the interaction of roi with its gene. we h ... | 1996 | 8763934 |
| phenotypes of dnaa mutants of escherichia coli sensitive to phenothiazine derivatives. | the activation of dnaa protein by cardiolipin is inhibited by fluphenazine in vitro. we therefore examined the sensitivity of temperature-sensitive dnaa mutants of escherichia coli to fluphenazine and other phenothiazine derivatives. among the eight dnaa mutants tested, dnaa5, dnaa46 dnaa602, and dnaa604, mutants with mutations in the putative atp binding site of dnaa protein, showed higher sensitivities to phenothiazine derivatives than did the wild-type strain. the dnaa508 and dnaa167 mutants, ... | 1996 | 8804395 |
| antibody expression from the core region of the human igh locus reconstructed in transgenic mice using bacteriophage p1 clones. | mice carrying transgenic human immunoglobulin gene miniloci can be used for the production of human monoclonal antibodies. the human variable region (v) gene segments in these miniloci undergo productive rearrangement in mouse lymphoid tissue to yield a population of b lymphocytes expressing a repertoire of antibodies. many of the miniloci studied to date have included only a small number of germline gene segments in an artificially compact configuration. here we describe the use of the bacterio ... | 1996 | 8812473 |
| generation of a transcriptional map for a 700-kb region surrounding the polycystic kidney disease type 1 (pkd1) and tuberous sclerosis type 2 (tsc2) disease genes on human chromosome 16p3.3. | a 700-kb region of dna in human chromosome 16p13.3 has been shown to contain the polycystic kidney disease 1 (pkd1) and the tuberous sclerosis type 2 (tsc2) disease genes. an estimated 20 genes are present in this region of chromosome 16. we have initiated studies to identify transcribed sequences in this region using a bacteriophage p1 contig containing 700 kb of dna surrounding the pkd1 and tsc2 genes. we have isolated 96 unique exon traps from this interval, with 23 of the trapped exons conta ... | 1996 | 8828041 |
| site-directed mutagenesis techniques in the study of escherichia coli serine hydroxymethyltransferase. | the 3340-bp fragment containing the escherichia coli glya gene coding for serine hydroxymethyltransferase was reduced in size by pcr, and the 1600-bp fragment obtained was cloned into the vector pbr322 in both orientations (5'-3', and 3'-5'). this dna manipulation allowed us to perform site-directed mutagenesis by pcr on the glya gene. to overcome the problem of the presence of wild-type protein in the various mutant enzyme preparations, the e. coli strain gs245 used to express recombinant serin ... | 1996 | 8860659 |
| organization of the mouse cardiac natriuretic peptide locus encoding bnp and anp. | the genes encoding the mouse atrial natriuretic peptide and b-type natriuretic peptide were previously shown to be physically linked on mouse chromosome 4 (steinhelper me, 1993, structure, expression, and genomic mapping of the mouse natriuretic peptide type-b gene. circ res 72: 984-992). in the present study the spatial relationship and orientation of the mouse atrial natriuretic peptide and b-type natriuretic peptide transcription units were identified and a physical map of the mouse cardiac n ... | 1996 | 8877792 |
| transgene coplacement and high efficiency site-specific recombination with the cre/loxp system in drosophila. | studies of gene function and regulation in transgenic drosophila are often compromised by the possibility of genomic position effects on gene expression. we have developed a method called transgene coplacement, in which any two sequences can be positioned at exactly the same site and orientation in the genome. transgene coplacement makes use of the bacteriophage p1 system of cre/loxp site-specific recombination, which we have introduced into drosophila. in the presence of a cre transgene driven ... | 1996 | 8889532 |
| structure of the human gene encoding the protein repair l-isoaspartyl (d-aspartyl) o-methyltransferase. | the protein l-isoaspartyl/d-aspartyl o-methyltransferase (ec 2.1.1.77) catalyzes the first step in the repair of proteins damaged in the aging process by isomerization or racemization reactions at aspartyl and asparaginyl residues. a single gene has been localized to human chromosome 6 and multiple transcripts arising through alternative splicing have been identified. restriction enzyme mapping, subcloning, and dna sequence analysis of three overlapping clones from a human genomic library in bac ... | 1996 | 8914929 |
| the bacteriophage p1 lytic replicon: directionality of replication and cis-acting elements. | we have identified the direction of replication of a bacteriophage p1 lytic replicon. this was accomplished by constructing lambda p1 lysogens that contain a functional p1 lytic replicon and analysing which of two nearby bacterial dna markers flanking the lambda prophage were amplified when that replicon was activated. we demonstrate that both dna markers are coordinately amplified, a result consistent with lytic replication proceeding in a bidirectional fashion. to analyze the role of various e ... | 1996 | 8917092 |
| bypass of lethality with mosaic mice generated by cre-loxp-mediated recombination. | the analysis of gene function based on the generation of mutant mice by homologous recombination in embryonic stem cells is limited if gene disruption results in embryonic lethality. mosaic mice, which contain a certain proportion of mutant cells in all organs, allow lethality to be circumvented and the potential of mutant cells to contribute to different cell lineages to be analyzed. to generate mosaic animals, we used the bacteriophage p1-derived cre-loxp recombination system, which allows gen ... | 1996 | 8939573 |
| construction of a 750-kb bacterial clone contig and restriction map in the region of human chromosome 21 containing the progressive myoclonus epilepsy gene. | the gene responsible for progressive myoclonus epilepsy of the unverricht-lundborg type (epm1) is located on human chromosome 21q22.3 in a region defined by recombination breakpoints and linkage disequilibrium. as part of an effort to clone the epm1 gene on the basis of its chromosomal location, we have constructed a 753-kb bacterial clone contig that encompasses the region containing the gene. because dna markers from the region did not identify intact yeast artificial chromosome (yac) clones a ... | 1996 | 8963899 |
| subregion- and cell type-restricted gene knockout in mouse brain. | using the phage p1-derived cre/loxp recombination system, we have developed a method to create mice in which the deletion (knockout) of virtually any gene of interest is restricted to a subregion or a specific cell type in the brain such as the pyramidal cells of the hippocampal ca1 region. the cre/loxp recombination-based gene deletion appears to require a certain level of cre protein expression. the brain subregional restricted gene knockout should allow a more precise analysis of the impact o ... | 1996 | 8980237 |
| production and characterization of human 293 cell lines expressing the site-specific recombinase cre. | we have constructed 293 cell lines expressing the site-specific cre recombinase from bacteriophage p1, that acts on a 34 bp target sequence called loxp. stably transformed cells were obtained by transfection with a plasmid containing cre and a selectable marker under the control of viral promoters. the resulting 293cre cell lines could be used to induce expression from adenovirus vectors containing reporter genes under the control of a cre responsive "molecular switch." high efficiency recombina ... | 1996 | 9131017 |
| genomic targeting with an mbp-cre fusion protein. | the cre recombinase of bacteriophage p1 catalyses site-specific recombination between lox-recombination target sites both in prokaryotic and eukaryotic cells and has thus become a popular tool in genetic research. stable, cre-mediated integration of dna sequences at pre-existing lox sites in the eukaryotic genome is facilitated when a cre recombinase protein rather than a cre-expression plasmid is used to direct site-specific recombination (baubonis and sauer (1993) nucleic acids res., 21, 2025- ... | 1996 | 8996087 |
| drosophila rosa gene, which when mutant causes aberrant photoreceptor oscillation, encodes a novel neurotransmitter transporter homologue. | the drosophila receptor oscillation a (rosa) mutations, which cause electroretinogram (erg) defects, including oscillations, were localized to the 24f4-25a2 region of chromosome 2l. genomic fragments from this region, isolated from bacteriophage p1 clones, included those that detect transcriptional defects in rosa mutants in rna blot experiments. one of these genomic fragments was used to screen a head cdna library. the largest cdna clone (3.6 kb) isolated was shown to rescue a rosa mutant in p ... | 1996 | 10876650 |
| efficient removal of loxp-flanked dna sequences in a gene-targeted locus by transient expression of cre recombinase in fertilized eggs. | the bacteriophage p1 cre/loxp site-specific recombination system is a useful tool for engineering chromosomal changes in animal cells. transient expression of the cre recombinase gene directly introduced into fertilized eggs by pronuclear injection has been reported to provide an efficient method of transgene modulation in fertilized eggs. in the present study, we examined the efficacy of this method to remove loxp-flanked dna sequences in a gene-targeted locus in fertilized eggs. we replaced a ... | 1997 | 9021742 |
| virulence gene deletion frequency is increased in shigella flexneri following conjugation, transduction, and transformation. | some commonly used methods for introducing dna provoke spontaneous loss of expression of a virulence gene located on the high molecular mass plasmid in shigella flexneri. the introduction of plasmid dna by calcium chloride-mediated transformation in strains harbouring wild-type or mutated copies of regulatory genes resulted in the loss of expression of an mxic-lacz reporter gene at high frequency, approaching 100% in some cases. lac- segregants arose whether or not the introduced plasmids harbou ... | 1997 | 9037774 |
| the cre recombinase cleaves the lox site in trans. | the cre protein is a conservative site-specific recombinase that is encoded by bacteriophage p1. its function in vivo is to resolve dimeric lysogenic p1 plasmids that arise by general recombination. in this way cre facilitates effective partition of the p1 prophage. cre is a member of the integrase family of conservative site-specific recombinases. cleavage of the dna by the integrases involves covalent attachment of a conserved nucleophilic tyrosine to the 3'-phosphoryl end at the site of the b ... | 1997 | 9038180 |
| [modification of gene targeting method for functional analysis of the target gene in vivo]. | gene targeting in es cells is a powerful tool to generate mice bearing predesigned mutations in the germ line. however, these mice carrying such constitutional mutations are often lethal and, therefore, we cannot study other functional aspects of the gene at later stages or in particular tissues. to inactivate the target gene in particular tissues or at particular stages of development, conditional gene inactivation based on the cre-loxp recombination system of bacteriophage p1 is considered one ... | 1997 | 9063484 |
| mechanism of protein remodeling by clpa chaperone. | clpa, a newly discovered atp-dependent molecular chaperone, remodels bacteriophage p1 repa dimers into monomers, thereby activating the latent specific dna binding activity of repa. we investigated the mechanism of the chaperone activity of clpa by dissociating the reaction into several steps and determining the role of nucleotide in each step. in the presence of atp or a nonhydrolyzable atp analog, the initial step is the self-assembly of clpa and its association with inactive repa dimers. clpa ... | 1997 | 9144162 |
| the type ic hsd loci of the enterobacteria are flanked by dna with high homology to the phage p1 genome: implications for the evolution and spread of dna restriction systems. | ecor124l, ecodxxl and ecoprrl are the known members of the type ic family of dna restriction and modification systems. the first three are carried on large, conjugative plasmids, while ecoprrl is chromosomally encoded. the enzymes are coded by three genes, hsdr, hsdm and hsds. analysis of the dna sequences upstream and downstream of the type ic hsd loci shows that all are highly homologous to each other and also to sequences present in the bacteriophage p1 genome. the upstream sequences include ... | 1997 | 9157244 |
| characterization of the lysogeny dna module from the temperate streptococcus thermophilus bacteriophage phi sfi21. | phage phi sfi21, the only temperate streptococcus thermophilus phage from our phage collection, showed extensive dna homology with virulent phages from lytic group i. southern blot hybridizations demonstrated that the phi sfi21-specific dna was clustered in an approximately 6.6-kb-long region, the putative lysogeny module. sequence analysis and database research identified an integrase within this module; orf 203 with homology to an anonymous orf 258 from the temperate lactococcal phage bk5-t; o ... | 1997 | 9201223 |
| the site-specific recombinase encoded by pind in shigella dysenteriae is due to the presence of a defective mu prophage. | the dna inversion systems are made up of an invertible dna segment and a site-specific recombinase gene. five systems are known in prokaryotes: the salmonella typhimurium h segment and hin gene (h-hin), phage mu g-gin, phage p1 c-cin, escherichia coli e14 p-pin, and shigella sonnei b-pinb systems. in this report a site-specific recombinase (pind) gene of shigella dysenteriae was cloned and sequenced. pind mediated inversion of five known segments at the same extent in e. coli. although one inv s ... | 1997 | 9202481 |
| characterization of the genomic structure and promoter of the mouse nad+-dependent 15-hydroxyprostaglandin dehydrogenase gene. | the mouse nad+-dependent 15-hydroxyprostaglandin dehydrogenase (15-pgdh) gene and its 5'-flanking region was cloned from a 129 mouse es bacteriophage p1 genomic library. the gene contains 7 exons and 6 introns and is 11.3 kb in length. the transcription initiation site was mapped at 35 bases upstream from the atg start codon. the nucleotide sequence of the 1.6 kb promoter region contains two tata boxes and a number of potential regulatory elements including sp1, cre, gre, ap1, ap2, nf-il6 and es ... | 1997 | 9207200 |
| a framework physical map of drosophila virilis based on p1 clones: applications in genome evolution. | the analysis of patterns of genome evolution may help to evaluate the evolutionary forces that shape the composition and organization of the genome. comparisons between the physical maps of divergent species can be used to identify conserved blocks of closely linked genes whose synteny is possibly under selective constraint. we have used in situ hybridization to determine the genomic position of 732 randomly selected clones from a bacteriophage p1 library of drosophila virilis. the resulting map ... | 1997 | 9215559 |
| brief expression of a gfp cre fusion gene in embryonic stem cells allows rapid retrieval of site-specific genomic deletions. | the cre dna recombinase of bacteriophage p1 has become a useful tool for precise genomic manipulation in embryonic stem (es) cells that have been gene modified by homologous recombination. we have re-engineered the cre gene to allow ready identification of living cre+cells by constructing a functional fusion between cre and an enhanced green fluorescent protein from aequorea victoria (gfps65t). the gfp cre fusion gene product rapidly targeted the nucleus in the absence of any exogenous nuclear l ... | 1997 | 9241248 |
| exclusion of bmp6 as a candidate gene for cleidocranial dysplasia. | cleidocranial dysplasia (ccd) is an autosomal dominant, generalized skeletal dysplasia in humans that has been mapped to the short arm of chromosome 6. we report linkage of a ccd mutation to 6p21 in a large family and exclude the bone morphogenetic protein 6 gene (bmp6) as a candidate for the disease by cytogenetic localization and genetic recombination. ccd was linked with a maximal two-point lod score of 7.22 with marker d6s452 at theta = 0. one relative with a recombination between d6s451 and ... | 1997 | 9268099 |
| a transgenic mouse line that retains cre recombinase activity in mature oocytes irrespective of the cre transgene transmission. | the cre/loxp site-specific recombination system derived from bacteriophage p1 provides a convenient tool for directed modifications of genomes in various organisms. to exploit cre-mediated manipulation of mouse genomic sequences at the zygote stage, we have developed a transgenic mouse line carrying the cag-cre transgene in which the cre gene is under control of the cytomegalovirus immediate early enhancer-chicken beta-actin hybrid (cag) promoter. the activity of the cre recombinase at early sta ... | 1997 | 9268708 |
| mutation of the htrb gene in a virulent salmonella typhimurium strain by intergeneric transduction: strain construction and phenotypic characterization. | the htrb gene product of haemophilus influenzae contributes to the toxicity of the lipooligosaccharide. the htrb gene encodes a 2-keto-3-deoxyoctulosonic acid-dependent acyltransferase which is responsible for myristic acid substitutions at the hydroxy moiety of lipid a beta-hydroxymyristic acid. mass spectroscopic analysis has demonstrated that lipid a from an h. influenzae htrb mutant is predominantly tetraacyl and similar in structure to lipid iv(a), which has been shown to be nontoxic in ani ... | 1997 | 9287009 |
| the modified nucleoside 2-methylthio-n6-isopentenyladenosine in trna of shigella flexneri is required for expression of virulence genes. | the virulence of the human pathogen shigella flexneri is dependent on both chromosome- and large-virulence-plasmid-encoded genes. a kanamycin resistance cassette mutation in the miaa gene (miaa::km sma), which encodes the trna n6-isopentyladenosine (i6a37) synthetase and is involved in the first step of the synthesis of the modified nucleoside 2-methylthio-n6-isopentenyladenosine (ms2i6a), was transferred to the chromosome of s. flexneri 2a by phage p1 transduction. in the wild-type bacterium, m ... | 1997 | 9294434 |
| a 3-mb sequence-ready contig map encompassing the multiple disease gene cluster on chromosome 11q13.1-q13.3. | despite the presence of several human disease genes on chromosome 11q13, few of them have been molecularly cloned. here, we report the construction of a contig map encompassing 11q13.1-q13.3 using bacteriophage p1 (p1), bacterial artificial chromosome (bac), and p1-derived artificial chromosome (pac). the contig map comprises 32 p1 clones, 27 bac clones, 6 pac clones, and 1 yac clone and spans a 3-mb region from d11s480 to d11s913. the map encompasses all the candidate loci of bardet-biedle synd ... | 1997 | 9405936 |
| construction of a 780-kb pac, bac, and cosmid contig encompassing the minimal critical deletion involved in b cell chronic lymphocytic leukemia at 13q14.3. | a putative tumor suppressor gene involved in b cell chronic lymphocytic leukemia (b-cll) was mapped to human chromosome 13q14.3 close to the genetic markers d13s25 and d13s319. we constructed a 780-kb-long contig composed of cosmids, bacterial artificial chromosomes, and bacteriophage p1-derived artificial chromosomes that provides essential information and tools for the positional cloning of this gene. the conting contains both flanking markers as well as several additional genetic markers, thr ... | 1997 | 9417905 |
| genomic targeting of a bicistronic dna fragment by cre-mediated site-specific recombination. | the cre-recombinase of bacteriophage p1 catalyses site-specific recombination between dna fragments containing loxp sites. targeting of predefined genomic loci can be achieved by cre-mediated linkage of a promoterless resistance marker gene to a floxed promoter pre-existing in the genome. in order to avoid the introduction of plasmid sequences into the host genome, we have constructed a series of plasmids in which the dna segment to be integrated is flanked by two loxp sites. we show here that t ... | 1997 | 9426252 |
| cloning and characterization of the ori region of psw1200 of erwinia stewartii: similarity with plasmid p1. | the ori region of an erwinia stewartii plasmid, psw1200 (106 kb), has been cloned and sequenced. this region consists of a gene encoding a protein which has 91% similarity and 73% identity with the repa protein of bacteriophage p1. the ori region also consists of eight copies of 19-bp iterons which are highly homologous to the iterons of p1. similar to plasmid p1, psw1200 replicon has a copy number of approximately 1. on the other hand, the copy number increases about ninefold if three of the it ... | 1997 | 9435016 |
| replication of plasmids derived from p1, f, r1, r6k and rk2 replicons in amino acid-starved escherichia coli stringent and relaxed strains. | replication of mini-plasmids derived from bacteriophage p1 and naturally existing plasmids f, r1, r6k and rk2 in otherwise isogenic rela+ and rela- escherichia coli strains during amino acid starvation and limitation was investigated. since it was previously demonstrated that inhibition of dna synthesis or amplification of plasmid dna may depend on the nature of deprived amino acid, we starved bacteria for five different amino acids. we found differential replication of all these plasmids but rk ... | 1997 | 9440285 |
| efficiency of recombination by cre transient expression in embryonic stem cells: comparison of various promoters. | the cre-loxp recombination system of bacteriophage p1 is frequently utilized in genetic manipulation in embryonic stem (es) cells. the level of cre expression is critical to induce loxp site-specific recombination in es cells. to compare the efficiency of recombination, we constructed four cre expression vectors driven by different promoters: cytomegarovirus/chicken beta-actin (cag) promoter, human polypeptide chain elongation factor 1alpha (hef-1alpha) promoter, mouse phosphoglycerate kinase-1 ... | 1997 | 9443813 |
| alu-polymerase chain reaction genomic fingerprinting technique identifies multiple genetic loci associated with pancreatic tumourigenesis. | dna fingerprinting can be used to detect genetic rearrangements in cancer that may be associated with activation of oncogenes and inactivation of tumour suppressor genes. we have developed a fingerprinting strategy based on polymerase chain reaction (pcr) amplification of genomic dna with primers specific for the alu repeat sequences, which are highly abundant in the human genome. this has been applied to dna from pancreatic cancer and paired normal samples to isolate and identify fragments of g ... | 1997 | 8993978 |
| structure and chromosomal localization of the mouse bombesin receptor subtype 3 gene. | bombesin (bn)-like peptides/neurotransmitters mediate a broad range of physiological funtions in the gastrointestinal tract and the central nervous system through binding to their specific, high-affinity mammalian bombesin receptors. this family of heptahelical, g-protein coupled receptors includes the gastrin-releasing peptide receptor (grp-r, or bb2), neuromedin b receptor (nmb-r, or bb1), and the bombesin receptor subtype 3 (brs-3, or bb3). the tissue distribution of brs-3 is quite dissimilar ... | 1998 | 9573346 |
| inducible gene targeting in mice using the cre/lox system. | molecular techniques now allow the design of precise genetic modifications in the mouse. not only can defined nucleotide changes be engineered into the genome of the mouse, but genetic switches can be designed to target expression or ablation of any gene (for which basic molecular information is available) to any tissue at any defined time. these strategies promise to contribute substantially to an increased understanding of individual gene function in development and pathogenesis. a powerful to ... | 1998 | 9608509 |
| transfer of p1 inserts into a yeast-bacteria shuttle vector by co-transformation mediated homologous recombination. | manipulation of genomic inserts cloned into the bacteriophage p1 vector is hindered by the large size of the inserts. we have used co-transformation mediated recombination between the yeast-bacteria shuttle vector, pclasper, and various p1 clones to transfer the entire insert from the p1 into pclasper. this results in the insert being stably maintained in yeast, facilitating mutagenesis by homologous recombination. the recombinant plasmid can subsequently be transferred to and stably maintained ... | 1998 | 9671827 |
| site-specific recombination using an epitope tagged bacteriophage p1 cre recombinase. | since the original description of cre mediated site-specific recombination in bacteriophage p1 (sternberg, n., hamilton, d., 1981 j. mol. biol., 150, 467-487), the cre-lox system of recombination has been widely used to manipulate prokaryotic and eukaryotic genomes. unfortunately, there are few means available to measure cre protein expression in vivo. we have constructed an expression vector wherein the cre protein is tagged at the carboxy terminus with an 11-amino-acid epitope to the herpes si ... | 1998 | 9714840 |
| cre mutants with altered dna binding properties. | the recombinase cre of bacteriophage p1 is a member of the family of site-specific recombinases and integrases that catalyze inter- and intramolecular dna rearrangements. to understand how this protein specifically recognizes its target sequence, we constructed cre mutants with amino acid substitutions in different positions of the presumptive dna binding region. here we present the results of in vitro dna binding and in vivo recombination experiments with these cre mutants. most substitutions o ... | 1998 | 9722507 |
| insulin-like growth factor-i affects perinatal lethality and postnatal development in a gene dosage-dependent manner: manipulation using the cre/loxp system in transgenic mice. | insulin-like growth factor-i (igf-i) is essential for cell growth, differentiation and postnatal development. a null mutation in igf-1 causes intrauterine growth retardation and perinatal lethality. the present study was designed to test the lower limit of igf-1 gene dosage that ensures survival and postnatal growth by using the cre/loxp system. mice with variable reductions in igf-i levels were generated by crossing eiia-cre transgenic mice and mice with loxp-flanked igf-1 locus (igf-1/flox). e ... | 1998 | 9731712 |
| cre-loxp-mediated inactivation of the alpha6a integrin splice variant in vivo: evidence for a specific functional role of alpha6a in lymphocyte migration but not in heart development. | two splice variants of the alpha6 integrin subunit, alpha6a and alpha6b, with different cytoplasmic domains, have previously been described. while alpha6b is expressed throughout the development of the mouse, the expression of alpha6a begins at 8.5 days post coitum and is initially restricted to the myocardium. later in ontogeny, alpha6a is found in various epithelia and in certain cells of the immune system. in this study, we have investigated the function of alpha6a in vivo by generating knock ... | 1998 | 9763436 |
| comparative mapping of distal murine chromosome 11 and human 17q21.3 in a region containing a modifying locus for murine plasma von willebrand factor level. | type 1 von willebrand disease (vwd) is a common inherited disorder characterized by mild to moderate bleeding and reduced levels of von willebrand factor (vwf). an animal model for human type 1 vwd, the riiis/j mouse strain, exhibits a prolonged bleeding time and reduced plasma vwf levels. we have previously mapped the defect in riiis/j to distal mouse chr 11, distinct from the vwf locus on chr 6. this locus, mvwf, was localized to an approximately 0.5-cm interval, tightly linked to gip, distal ... | 1998 | 9806826 |
| comparative kinetic analysis of flp and cre recombinases: mathematical models for dna binding and recombination. | the integrase class site specific recombinases flp from saccharomyces cerevisiae, and cre from bacteriophage p1, have been extensively used to direct dna rearrangements in heterologous organisms. although their reaction mechanisms have been relatively well characterised, little comparative analysis of the two enzymes has been published. we present a comparative kinetic analysis of flp and cre, which identifies important differences. gel mobility shift assays show that cre has a higher affinity f ... | 1998 | 9813124 |
| accessory genes in the dara operon of bacteriophage p1 affect antirestriction function, generalized transduction, head morphogenesis, and host cell lysis. | bacteriophage p1 mutants with the 8.86-kb region between the invertible c-segment and the residential is1 element deleted from their genome are still able to grow vegetatively and to lysogenize stably, but they show several phenotypic changes. these include the formation of minute plaques due to delayed cell lysis, the abundant production of small-headed particles, a lack of specific internal head proteins, sensitivity to type i host restriction systems, and altered properties to mediate general ... | 1998 | 9813202 |
| complete dna sequence and detailed analysis of the yersinia pestis kim5 plasmid encoding murine toxin and capsular antigen. | yersinia pestis, the causative agent of plague, harbors at least three plasmids necessary for full virulence of the organism, two of which are species specific. one of the y. pestis-specific plasmids, pmt1, is thought to promote deep tissue invasion, resulting in more acute onset of symptoms and death. we determined the entire nucleotide sequence of y. pestis kim5 pmt1 and identified potential open reading frames (orfs) encoded by the 100,990-bp molecule. based on codon usage for known yersinial ... | 1998 | 9826348 |
| the potential of integrons and connected programmed rearrangements for mediating horizontal gene transfer. | site-specific recombination of integrons, mediates transfer of single genes in small genomes and plasmids. recent data suggest that new genes are recruited to the cassettes--the units moved by integrons. integrons are resident in a class of transposons with pronounced target selectivity for resolution loci in broad host range plasmids. a resulting network of programmed transfer routes, with potential offshoots reaching into eukaryotic cells, may channel genes to unexpectedly remote organisms. it ... | 1998 | 9850680 |