| conjugative transfer of enterococcus faecalis plasmid pad1: nucleotide sequence and transcriptional fusion analysis of a region involved in positive regulation. | the enterococcus faecalis plasmid pad1 undergoes conjugative transfer in response to cad1, a peptide sex pheromone emitted by potential bacterial recipients. regulation of pad1 transfer involves a number of plasmid-encoded determinants:iad, which determines a peptide-competitive inhibitor iad1; signal sensing and transducing elements; and negative and positive regulators. the key positive regulator(s) of the pheromone response is believed to be encoded within a segment designated the e region of ... | 1992 | 1315730 |
| c-terminal identification of ad74, a proteolytic product of enterococcus faecalis aggregation substance: application of liquid chromatography/mass spectrometry. | sexual aggregation involved in conjugative transfer of enterococcus faecalis plasmid pad1 is enhanced by the sex pheromone cad1, which is excreted from recipient cells. a membrane-anchored 137 kda protein is a pad1-encoded aggregation substance designated asal, which is responsible for cell-cell contact and leads to the aggregation of cells. an ad74 protein is a proteolytic product corresponding to the n-terminal half of asal. the c-terminal of ad74 was identified as lysine at position 510 (k-51 ... | 1992 | 1368124 |
| aminoglycoside-resistant streptococcus and enterococcus species isolated from bovine mammary secretions. | a total of 117 isolates representing four streptococcus species and 20 isolates representing two enterococcus species from bovine mammary secretions were examined for resistance to streptomycin, kanamycin, and gentamicin. resistance to streptomycin (85.4%) was most prevalent, followed by kanamycin (19%) and gentamicin (2.2%). minimum inhibitory concentration of streptomycin for most organisms examined ranged from 16 to 250 micrograms/ml. for kanamycin, the minimum inhibitory concentration for mo ... | 1992 | 1578037 |
| sequence analysis of enterococcus faecalis aggregation substance encoded by the sex pheromone plasmid pad1. | the location of the structural gene for aggregation substance on the sex pheromone plasmid pad1 of enterococcus faecalis was determined using an oligonucleotide deduced from the n-terminal amino acid sequence of the purified protein. the nucleotide sequence was determined for the corresponding region and two open reading frames (orfs) could be identified. orf1 codes for a small (mr 13,160) acidic protein of unknown function. the gene for aggregation substance (named asa1) was found to code for a ... | 1990 | 2120541 |
| genetic analysis of the pad1 hemolysin/bacteriocin determinant in enterococcus faecalis: tn917 insertional mutagenesis and cloning. | thirty-seven nonhemolytic/nonbacteriocinogenic mutations in enterococcus (streptococcus) faecalis plasmid pad1 were generated by tn917 insertion. all were found to belong to one of two complementation classes. each class of mutants secreted either hemolysin/bacteriocin (hly/bac) component a or l into the culture medium. dna encoding hly/bac was cloned in escherichia coli in which both components of the hemolysin were expressed individually and collectively. the region encoding components a and l ... | 1990 | 2152897 |
| regulation of the pad1 sex pheromone response in enterococcus faecalis: construction and characterization of lacz transcriptional fusions in a key control region of the plasmid. | strains carrying the enterococcus (formerly streptococcus) faecalis plasmid pad1 responded to exogenous sex pheromone by inducing a number of gene products which facilitated mating. a 7-kilobase region of pad1 was identified which contained genes that are important for the regulation of this response. using the transposon tn917-lac delivery vector ptv32ts, we generated a number of fusions that allowed us to examine transcription in this region. at least three transcriptional units were identifie ... | 1988 | 2842316 |
| a conjugative transposon (tn919) in streptococcus sanguis. | streptococcus sanguis fc1, originally isolated from dental plaque, was found to be naturally resistant to tetracycline. although no plasmid dna could be detected, tetracycline resistance was transferable in filter matings to streptococcus faecalis fa2-2. again, no plasmid dna was detectable in transconjugants, and the latter could donate tetracycline resistance to s. faecalis, s. sanguis, and streptococcus lactis. the tetracycline resistance element was able to transpose to several sites on the ... | 1985 | 2981772 |
| transfer of the conjugal tetracycline resistance transposon tn916 from streptococcus faecalis to staphylococcus aureus and identification of some insertion sites in the staphylococcal chromosome. | the streptococcus faecalis pheromone-dependent conjugative plasmid pad1::tn916 and the membrane filter-dependent conjugative plasmid ppd5::tn916 were used to introduce tn916 into staphylococcus aureus by intergeneric protoplast fusions and intergeneric membrane-filter matings. in recombinants obtained by protoplast fusion where no plasmid dna could be detected, tetracycline resistance resulted from transposition of tn916 from pad1 to the s. aureus chromosome. transformation analyses showed that ... | 1987 | 3032908 |
| two conjugation systems associated with streptococcus faecalis plasmid pcf10: identification of a conjugative transposon that transfers between s. faecalis and bacillus subtilis. | the tetracycline resistance plasmid pcf10 (58 kilobases [kb]) of streptococcus faecalis possesses two separate conjugation systems. a 25-kb region of the plasmid (designated tra) was shown previously to determine pheromone response and conjugation functions required for transfer of pcf10 between s. faecalis cells (p. j. christie and g. m. dunny, plasmid 15:230-241, 1986). when s. faecalis cells were mixed with bacillus subtilis in broth, tetracycline resistance was transferred from s. faecalis. ... | 1987 | 3034859 |
| transfer functions of the streptococcus faecalis plasmid pad1: organization of plasmid dna encoding response to sex pheromone. | the conjugative plasmid pad1 (59.6 kilobases) of streptococcus faecalis shows a 10,000-fold increase in transfer frequency following induction by the sex pheromone cad1. mutagenesis of the plasmid with transposon tn917 was undertaken to determine the region(s) of pad1 required for the mating response. the relevant genetic material was found to be distributed over a 31.2-kilobase contiguous region of the plasmid. although insertions in two previously identified regions (traa and trab) exhibited i ... | 1987 | 3038841 |
| identification of pheromone-induced surface proteins in streptococcus faecalis and evidence of a role for lipoteichoic acid in formation of mating aggregates. | the conjugative transfer of the streptococcus faecalis plasmid pad1 is characterized by a 10,000-fold increase in frequency following sex pheromone (cad1) induction. before the increase in plasmid transfer, donor cells synthesize a proteinaceous adhesin that facilitates the formation of mating aggregates. four novel surface proteins appearing after exposure of pad1-containing cells to sex pheromone have been identified. thirty minutes after induction, a 130-kilodalton (kda) protein was detectabl ... | 1986 | 3093466 |
| streptococcus faecalis sex pheromone (cad1) response: evidence that the peptide inhibitor excreted by pad1-containing cells may be plasmid determined. | streptococcus faecalis strains harboring the conjugative plasmid pad1 excrete a small peptide, iad1, which inhibits the sex pheromone cad1. studies making use of the host strain streptococcus faecium 9790, which normally does not excrete peptide pheromones, suggest that iad1 may be determined directly by pad1. | 1987 | 3107004 |
| hemolysin of streptococcus faecalis subspecies zymogenes contributes to virulence in mice. | the conjugative plasmid pad1 (56.7 kilobases) in streptococcus faecalis confers hemolysin-bacteriocin (hly-bcn) expression and a mating response to the sex pheromone cad1 excreted by recipient cells. we examined the contribution of hemolysin to pathogenicity in intraperitoneally infected mice by using tn916 and tn917 insertion mutants altered in hemolysin expression. strains exhibiting the normal hemolysin phenotype were significantly more virulent than the nonhemolytic insertion mutants. a muta ... | 1984 | 6086531 |
| dna protection with the dna methylase m . bbvi from bacillus brevis var. gb against cleavage by the restriction endonucleases psti and pvuii. | bamhi fragments of the bacillus brevis var. gb plasmid pad1 have been cloned in escherichia coli hb101 using pbr322 plasmid as a vector. the analysis of the recombinant plasmids showed that additional psti sites had appeared in cloned fragments of pad1. methylation of the recombinant plasmids in vitro by enzymes from b. brevis gb cells blocks cleavage at these additional psti sites of cloned pad1 fragments and at the psti site of pbr322. among dna methylases of b. brevis gb, the cytosine dna met ... | 1980 | 6248417 |
| evidence for a chromosome-borne resistance transposon (tn916) in streptococcus faecalis that is capable of "conjugal" transfer in the absence of a conjugative plasmid. | streptococcus faecalis strain ds16 harbors the conjugative hemolysin-bacteriocin plasmid pad1 (35 megadaltons) and the nonconjugative r-plasmid pad2 determining resistance to streptomycin, kanamycin, and erythromycin; a tetracycline resistance (tetr) determinant is located on the chromosome. when strain ds16 was mated (on membrane filters) with the plasmid-free strain jh2-2, tetr transconjugants could be obtained at a frequency of about 10(-6) per recipient. analyses of transconjugants showed th ... | 1981 | 6257641 |
| genetic analysis of the pad1 pheromone response in streptococcus faecalis, using transposon tn917 as an insertional mutagen. | the conjugative plasmid pad1 (56.7 kilobases) in streptococcus faecalis has been shown to confer a mating response to the sex pheromone cad1 excreted by recipient strains. the response is characterized by the synthesis of a proteinaceous adhesin which coats the surface of the pad1 -containing donor cell and facilitates the formation of mating aggregates. donors exposed to cad1 -containing filtrates of recipients undergo self-aggregation (clumping), an event believed to be associated with an inte ... | 1984 | 6327637 |
| isolation and structure of the bacterial sex pheromone, cad1, that induces plasmid transfer in streptococcus faecalis. | the streptococcus faecalis sex pheromone cad1, which is involved in the conjugative transfer of the hemolysin plasmid pad1, has been isolated and its structure determined. its mr is 818 and its amino acid sequence is h-leu-phe-ser-leu-val-leu-ala-gly-oh. a replicate of the pheromone synthesized by the liquid-phase method showed the same biological activity and chromatographic behavior as the isolated cad1. pheromone activity was detectable at a concentration of approximately 5 x 10(-11) m. | 1984 | 6437872 |
| genetic structure of the enterococcus faecalis plasmid pad1-encoded cytolytic toxin system and its relationship to lantibiotic determinants. | pheromone-responsive conjugative plasmids are unique to the species enterococcus faecalis. many pheromone-responsive plasmids, including those frequently isolated from sites of infection, express a novel cytolysin that possesses both hemolytic and bacteriocin activities. further, this cytolysin has been shown to be a toxin in several disease models. in the present study, nucleotide sequence determination, mutagenesis, and complementation analysis were used to determine the organization of the e. ... | 1994 | 7961506 |
| characterization of the determinant (trab) encoding sex pheromone shutdown by the hemolysin/bacteriocin plasmid pad1 in enterococcus faecalis. | pad1 is a hemolysin/bacteriocin plasmid originally identified in enterococcus faecalis ds16. it encodes a mating response to a peptide sex pheromone, cad1, secreted by recipient bacteria. once pad1 is acquired, production of the pheromone ceases--a trait related in part to a determinant designated trab. here we report the nucleotide sequence of trab and the position of several transposon insertions resulting in the characteristic self-induction phenotype. the deduced product has a mass of 43.7 k ... | 1994 | 8029329 |
| studies on excision of conjugative transposons in enterococci: evidence for joint sequences composed of strands with unequal numbers of nucleotides. | we determined the nucleotide sequence of polymerase chain reaction products resulting from amplification of joint regions created after excision of transposons tn5381 and tn916 from a single site within plasmid pad1. for both transposons, two joint sequences were observed. one (atagat) was six nucleotides in length and identical to one of the junction sequences flanking the integrated transposon. this sequence also represents the original target sequence within pad1. the other (tatgt (tn5381) or ... | 1994 | 8058825 |
| a lipoprotein signal peptide encoded by the staphylococcal conjugative plasmid psk41 exhibits an activity resembling that of enterococcus faecalis pheromone cad1. | the trah gene of the staphylococcal conjugative plasmid psk41 has recently been shown to encode a lipoprotein (n. firth, k. p. ridgway, m. e. byrne, p. d. fink, l. johnson, i. t. paulsen, and r. a. skurray, gene 136:13-25, 1993). here we report that trah encodes a product recognized as a pheromone by enterococcus faecalis cells harboring the conjugative plasmid pad1. the mature trah product is not essential for this phenomenon, as expression of pheromone-like activity was found to require sequen ... | 1994 | 8083183 |
| plasmid-associated hemolysin and aggregation substance production contribute to virulence in experimental enterococcal endocarditis. | a rabbit endocarditis model was utilized to evaluate the virulence conferred by the conjugative plasmid pad1 with the following strains: enterococcus faecalis plasmid-free fa2-2 and fa2-2 containing plasmids pad1 (hemolysin and aggregation substance positive), pam9058 (insertional inactivation of hemolysin), and pam944 or pam947 (insertional inactivation of aggregation substance). all isolates were similar in ability to produce endocarditis. mean vegetation weight was greater in animals inoculat ... | 1993 | 8285637 |
| cloning and characterization of a region of the enterococcus faecalis conjugative plasmid, pcf10, encoding a sex pheromone-binding function. | in order to investigate the mechanism by which peptide sex pheromones induce expression of the conjugation functions of certain enterococcus faecalis plasmids, a biological assay was developed to measure the ability of cells carrying the conjugative plasmid pcf10 to bind the sex pheromone ccf10. the data indicated that pcf10 endows its host e. faecalis cell with the ability to specifically remove (apparently by irreversible binding) ccf10 activity from culture medium. the pcf10 dna encoding this ... | 1993 | 8349565 |
| characterization of the trac determinant of the enterococcus faecalis hemolysin-bacteriocin plasmid pad1: binding of sex pheromone. | pad1, a conjugative, 60-kb, hemolysin-bacteriocin plasmid in enterococcus faecalis, encodes a mating response to a small peptide sex pheromone, cad1, secreted by potential recipient bacteria. a gene, trac, encoding a 60.7-kda protein with a typical amino terminal signal peptide, was identified within a region that appears to encode a product that binds to exogenous pheromone. a cloned segment of dna containing trac resulted in specific binding of cells to synthetic cad1. the putative trac produc ... | 1993 | 8349566 |
| identification, characterization, and nucleotide sequence of a region of enterococcus faecalis pheromone-responsive plasmid pad1 capable of autonomous replication. | a 5-kbp region of pad1, previously shown to be capable of supporting replication, copy control, and stable inheritance of the plasmid, was cloned into a replicon probe vector and subjected to transposon insertional mutagenesis. transposon inserts identifying essential replication, copy control, and stability functions were isolated. deletion of stability functions not essential for replication resulted in delimitation of a basic replicon. the complete dna sequence of this approximately 3-kbp reg ... | 1993 | 8384618 |
| cloning and characterization of the uvr (ultraviolet resistance) gene on conjugative plasmid pad1 of enterococcus faecalis. | | 1995 | 8586249 |
| enterococcus faecalis plasmid pad1 replication and maintenance. | a determinant has been identified which is required for the stable inheritance of a replicon isolated from the pheromone-responsive e. faecalis plasmid pad1. this determinant, called par, is encoded on a dna fragment no larger than 457 bp and directs the production of two small rnas of approximately 250 (rnai) and 145 (rnaii) nucleotides. mutations affecting par rna production also affected plasmid stability, indicating that these rnas play a central role in par function. putative transcription ... | 1995 | 8586250 |
| sequence and analysis of the replication region of the staphylococcus xylosus plasmid psx267. | the region of the 29.5-kb plasmid psx267 from staphylococcus xylosus dsm 20267 that is required for autonomous replication in staphylococci was isolated on a 1.8-kb dna fragment. the sequence analysis of the fragment yielded two open reading frames, repa and orf2, encoding proteins of 37.2 and 13.2 kda, respectively. the deduced amino acid sequence of repa showed similarity to the replication initiator protein of plasmid pad1 from enterococcus faecalis, to two proteins of unknown function encode ... | 1996 | 8982076 |
| the origin of transfer (orit) of the enterococcal, pheromone-responding, cytolysin plasmid pad1 is located within the repa determinant. | the highly conjugative pad1 plasmid encodes a mating response to the peptide sex pheromone cad1 secreted by recipient strains of enterococcus faecalis. the location of the origin of transfer (orit) was determined through the ability to mobilize the escherichia coli-e. faecalis shuttle plasmid pam401 carrying specific segments of pad1. the orit sequence was found to be completely within the repa determinant known to be required for plasmid maintenance. | 1997 | 9073585 |
| regulation of transfer of the enterococcus faecalis pheromone-responding plasmid pad1: temperature-sensitive transfer mutants and identification of a new regulatory determinant, trad. | the enterococcal, conjugative, cytolysin plasmid pad1 confers a mating response to the peptide sex pheromone cad1 secreted by plasmid-free strains of enterococcus faecalis. cells carrying pam714, a pad1::tn917 derivative with wild-type conjugation properties, were mutagenized with ethyl methanesulfonate to obtain variants that were induced (in the absence of pheromone) to transfer plasmid dna upon shifting from 32 to 42 degrees c. of 31 such mutants generated, the results of analyses of 7 are pr ... | 1997 | 9150221 |
| cloning and genetic analysis of the uv resistance determinant (uvr) encoded on the enterococcus faecalis pheromone-responsive conjugative plasmid pad1. | the conjugative pheromone-responsive plasmid pad1 (59.6 kb) of enterococcus faecalis encodes a uv resistance determinant (uvr) in addition to the hemolysin-bacteriocin determinant. pad1 enhances the uv resistance of wild-type e. faecalis fa2-2 and e. faecalis uv202, which is a uv-sensitive derivative of e. faecalis jh2-2. a 2.972-kb fragment cloned from between 27.7 and 30.6 kb of the pad1 map conferred uv resistance function on uv202. sequence analysis showed that the cloned fragment contained ... | 1997 | 9393713 |
| regulation of the pad1 sex pheromone response of enterococcus faecalis by direct interaction between the cad1 peptide mating signal and the negatively regulating, dna-binding traa protein. | the enterococcus faecalis conjugative plasmid pad1 (60 kb) encodes a mating response to the recipient-produced peptide sex pheromone cad1. the response involves two key plasmid-encoded regulatory proteins: trae1, which positively regulates all or most structural genes relating to conjugation, and traa, which binds dna and negatively regulates expression of trae1. in vitro studies that included development of a dna-associated protein-tag affinity chromatography technique showed that traa (37.9 kd ... | 1998 | 9600983 |
| regulation of the enterococcus faecalis pad1-related sex pheromone response: analyses of trad expression and its role in controlling conjugation functions. | the enterococcus faecalis haemolysin plasmid pad1 (60 kb) confers a conjugative mating response to an octapeptide sex pheromone (cad1) secreted by plasmid-free strains. the response involves two plasmid-borne regulatory determinants: trae1, whose product positively regulates all or most conjugation-related structural genes; and traa, whose product negatively regulates trae1 by controlling transcriptional readthrough of an upstream termination site (tts1/tts2). traa binds to the promoter region o ... | 1998 | 9791182 |
| isolation of a derivative of escherichia coli-enterococcus faecalis shuttle vector pam401 temperature sensitive for maintenance in e. faecalis and its use in evaluating the mechanism of pad1 par-dependent plasmid stabilization. | a derivative of the escherichia coli-enterococcus faecalis shuttle vector pam401 was isolated by mutagenesis in an e. coli mutator strain. this plasmid, designated pam401ts, was more than an order of magnitude less stable at 38 degreesc than at 30 degreesc in the e. faecalis host strain jh2-2. the e. faecalis plasmid pad1-encoded par stability locus was cloned onto pam401ts, and its effects on plasmid stability and host cell viability were assessed. it was found that par stabilized pam401ts at 3 ... | 1998 | 9806859 |
| enterococcus faecalis pheromone-responding plasmid pad1 gives rise to an aggregation (clumping) response when cells are exposed to subinhibitory concentrations of chloramphenicol, erythromycin, or tetracycline. | the enterococcus faecalis conjugative cytolysin plasmid pad1 encodes a specific aggregation (clumping) response to the peptide sex pheromone cad1 secreted by plasmid-free strains. here it is shown that, in the absence of cad1, exposure of e. faecalis cells harboring pad1 to subinhibitory concentrations of chloramphenicol, erythromycin, or tetracycline also results in an aggregation response that appears related to a stress-sensitive mechanism associated with a component of the pheromone response ... | 1999 | 9887311 |
| identification and characterization of a determinant (eep) on the enterococcus faecalis chromosome that is involved in production of the peptide sex pheromone cad1. | plasmid-free strains of enterococcus faecalis secrete a peptide sex pheromone, cad1, which specifically induces a mating response by donors carrying the hemolysin plasmid pad1 or related elements. a determinant on the e. faecalis og1x chromosome has been found to encode a 46.5-kda protein that plays an important role in the production of the extracellular cad1. wild-type e. faecalis og1x cells harboring a plasmid chimera carrying the determinant exhibited an eightfold enhanced production of cad1 ... | 1999 | 10498702 |
| pheromone-regulated expression of sex pheromone plasmid pad1-encoded aggregation substance depends on at least six upstream genes and a cis-acting, orientation-dependent factor. | conjugative transfer of enterococcus faecalis-specific sex pheromone plasmids relies on an adhesin, called aggregation substance, to confer a tight cell-to-cell contact between the mating partners. to analyze the dependence of pad1-encoded aggregation substance, asa1, on pheromone induction, a variety of upstream fragments were fused to an alpha-amylase reporter gene, amyl, by use of a novel promoter probe vector, pamy-em1. for pheromone-regulated alpha-amylase activity, a total of at least six ... | 2000 | 10850999 |
| completion of the nucleotide sequence of the enterococcus faecalis conjugative virulence plasmid pad1 and identification of a second transfer origin. | pad1 is a 59.3-kb plasmid in enterococcus faecalis that has been the subject of intense investigation with regard to its pheromone-inducible conjugation behavior as well as its contribution to virulence. approximately two-thirds of the pad1 nucleotide sequence has been previously reported. here we report on an analysis of the final approximately 22 kb, a significant portion of which is believed to encode structural genes associated with conjugation. the conjugation-related region was also found ... | 2001 | 11591137 |
| antisense rna regulation of the par post-segregational killing system: structural analysis and mechanism of binding of the antisense rna, rnaii and its target, rnai. | the par stability determinant of the enterococcus faecalis plasmid pad1 is the first antisense rna regulated post-segregational killing system (psk) identified in a gram-positive organism. par encodes two small, convergently transcribed rnas, designated rnai and rnaii, which are the toxin and antitoxin of the par psk system respectively. rnai encodes an open reading frame for a 33 amino acid toxin called fst. expression of fst is regulated post-transcriptionally by rnaii. rnaii interacts with rn ... | 2001 | 11703673 |
| identification of the cad1 sex pheromone precursor in enterococcus faecalis. | the enterococcus faecalis virulence plasmid pad1 encodes a mating response induced by exposure to an octapeptide sex pheromone, cad1, secreted by plasmid-free enterococci. the determinant for the pheromone in e. faecalis fa2-2, designated cad, was found to encode a 309-amino-acid lipoprotein precursor with the last 8 residues of its 22-amino acid signal sequence representing the cad1 moiety. the lipoprotein moiety contained two 77-amino-acid repeats (70% identity) separated by 45 residues. the n ... | 2002 | 11889094 |
| replication of enterococcus faecalis pheromone-responding plasmid pad1: location of the minimal replicon and oriv site and repa involvement in initiation of replication. | the hemolysin-determining plasmid pad1 is a member of a widely disseminated family of highly conjugative elements commonly present in clinical isolates of enterococcus faecalis. the determinants repa, repb, and repc, as well as adjacent iteron sequences, are believed to play important roles in pad1 replication and maintenance. the repa gene encodes an initiator protein, whereas repb and repc encode proteins related to stability and copy number. the present study focuses specifically on repa and ... | 2004 | 15262938 |
| specific control of endogenous ccf10 pheromone by a conserved domain of the pcf10-encoded regulatory protein prgy in enterococcus faecalis. | conjugative transfer of enterococcus faecalis plasmid pcf10 is induced by the heptapeptide pheromone ccf10. ccf10 produced by plasmid-free recipient cells is detected by pcf10-containing donor cells, which respond by induction of plasmid-encoded transfer functions. the pcf10-encoded membrane protein prgy is essential to prevent donor cells from responding to endogenously produced pheromone while maintaining the ability to respond to pheromone from an exogenous source; this function has not been ... | 2005 | 15995198 |
| pam401-based shuttle vectors that enable overexpression of promoterless genes and one-step purification of tag fusion proteins directly from enterococcus faecalis. | two novel enterococcus faecalis-escherichia coli shuttle vectors that utilize the promoter and ribosome binding site of baca on the e. faecalis plasmid ppd1 were constructed. the vectors were named pmgs100 and pmgs101. pmgs100 was designed to overexpress cloned genes in e. coli and e. faecalis and encodes the baca promoter followed by a cloning site and stop codon. pmgs101 was designed for the overexpression and purification of a cloned protein fused to a strep-tag consisting of 9 amino acids at ... | 2001 | 11229919 |
| emerging plasmid-encoded antisense rna regulated systems. | classic antisense rna research has focused on detailed examination of a few plasmid-encoded systems whilst more recent efforts have focused on chromosomally encoded small rnas. recent work on newly identified plasmid-encoded antisense rnas suggest that there is still much to learn from them about the versatility of regulatory rnas. the alpha-proteobacterial repabc plasmids produce an antisense rna that regulates the replication initiator independently of the partition proteins encoded in the sam ... | 2007 | 17376732 |
| antisense rna regulation of the pad1 par post-segregational killing system requires interaction at the 5' and 3' ends of the rnas. | the par stability determinant of the enterococcus faecalis plasmid pad1 is the first antisense rna-regulated post-segregational killing system (psk) identified in a gram-positive organism. par encodes two small, convergently transcribed rnas, designated rna i and rna ii, which are the toxin and antidote of the par psk system respectively. rna i encodes an open reading frame for a 33-amino-acid toxin called fst. expression of fst is regulated post-transcriptionally by rna ii. in this paper, rna i ... | 2000 | 10931359 |
| the antisense rna of the par locus of pad1 regulates the expression of a 33-amino-acid toxic peptide by an unusual mechanism. | the par stability determinant of the enterococcus faecalis plasmid pad1 is the first antisense rna-regulated post-segregational killing system (psk) identified in a gram-positive organism. par encodes two small, convergently transcribed rnas, designated rna i and rna ii, which are the toxin and antidote of the par psk system respectively. rna i encodes an open reading frame of 33 codons designated fst. the results presented here demonstrate that the peptide encoded by fst is the par toxin. the f ... | 2000 | 10931358 |
| analysis of the clumping-mediating domain(s) of sex pheromone plasmid pad1-encoded aggregation substance. | aggregation substance, a cell surface adhesin encoded on sex-pheromone plasmids exclusively found in the opportunistic pathogen enterococcus faecalis, displays a dual function in that it mediates (a) adhesion to host tissues and (b) aggregation of e. faecalis cells to result in efficient plasmid transfer. while there have been many investigations regarding the regulation of inducible plasmid transfer and involvement in pathogenicity, nearly nothing is known about the structural basis of clumping ... | 1998 | 9874218 |
| [detecting hematolysis of enterococcus from sheep]. | to characterize hematolysis of enterococcus from sheep. | 2008 | 18837371 |
| isolation of vanb-type enterococcus faecalis strains from nosocomial infections: first report of the isolation and identification of the pheromone-responsive plasmids pmg2200, encoding vanb-type vancomycin resistance and a bac41-type bacteriocin, and pmg2201, encoding erythromycin resistance and cytolysin (hly/bac). | eighteen identical vanb-type enterococcus faecalis isolates that were obtained from different hospitalized patients were examined for their drug resistance and plasmid dnas. of the 18 strains, 12 strains exhibited resistance to erythromycin (em), gentamicin (gm), kanamycin (km), tetracycline (tc), and vancomycin (van) and produced cytolysin (hly/bac) and a bacteriocin (bac) active against e. faecalis strains. another six of the strains exhibited resistance to gm, km, tc, and van and produced a b ... | 2009 | 19029325 |
| an intramolecular upstream helix ensures the stability of a toxin-encoding rna in enterococcus faecalis. | the par stability determinant is required for the stable inheritance of the plasmid pad1 in its native host, enterococcus faecalis. it is the only antisense rna-regulated addiction module identified to date in gram-positive bacteria. it encodes two small, convergently transcribed rnas, rna i and rna ii. rna i encodes the fst toxin and rna ii acts as the antitoxin by interacting with rna i posttranscriptionally. as the toxin-encoding component of the system, it is important that rna i is more sta ... | 2009 | 19103923 |
| identification and characterization of a family of toxin-antitoxin systems related to the enterococcus faecalis plasmid pad1 par addiction module. | the par locus of the enterococcus faecalis plasmid pad1 is an rna-regulated addiction module encoding the peptide toxin fst. homology searches revealed that fst belongs to a family of at least nine related peptides encoded on the chromosomes and plasmids of six different gram-positive bacterial species. comparison of an alignment of these peptides with the results of a saturation mutagenesis analysis indicated regions of the peptides important for biological function. examination of the genetic ... | 2009 | 19542006 |
| functional analysis of the enterococcus faecalis plasmid pad1-encoded stability determinant par. | the molecular organization and functional characteristics of the pad1 replicon-encoded par stability determinant were examined. par encodes two convergently transcribed rnas of approximately 210 and 65 nucleotides designated rna i and rna ii, respectively. the sequence of rna ii is largely complementary to rna i, suggesting that rna ii could regulate rna i function as an anti-sense rna. results of functional studies are consistent with a role for par as a post-segregational killing system, the f ... | 1996 | 8861204 |
| the corynebacterium xerosis composite transposon tn5432 consists of two identical insertion sequences, designated is1249, flanking the erythromycin resistance gene ermcx. | analysis of the 50-kb r-plasmid ptp10 from the clinical isolate corynebacterium xerosis m82b revealed that the erythromycin resistance gene, ermcx, is located on a 4524-bp composite transposable element, tn5432. the ends of tn5432 are identical, direct repeats of an insertion sequence, designated is1249, encoding a putative transposase of the is256 family. is1249 consists of 1385 bp with 45/42 imperfect terminal inverted repeats. the nucleotide sequence of the 1754-bp tn5432 central region is 99 ... | 1995 | 8559800 |
| sex pheromone plasmid pad1-encoded aggregation substance of enterococcus faecalis is positively regulated in trans by trae1. | sex-pheromone-plasmid-bearing strains of enterococcus faecalis react with sex pheromone to induce the expression of an adhesin, the so-called aggregation substance, on their cell surface. here we show that, by complementation studies, for sex-pheromone plasmid pad1, expression of the structural gene asa1, coding for an aggregation substance, is mediated by a diffusible factor encoded on pad1. we were able to demonstrate that a small open reading frame, trae1, is sufficient for transcription of t ... | 1993 | 8508803 |
| biochemical, immunological and ultrastructural characterization of aggregation substances encoded by enterococcus faecalis sex-pheromone plasmids. | the sex-pheromone system of enterococcus faecalis can be viewed as a unique and highly efficient plasmid-collection mechanism. the contact needed for transfer of the conjugative sex-pheromone plasmids is mediated by an adhesin, called aggregation substance, which is encoded by these plasmids. we show here that for 17 of the 18 sex-pheromone plasmids (pam373 being the exception) described to date, their adhesins are immunologically related to each other. in each case, we observed the presence of ... | 1993 | 8436129 |
| tn916 target dna sequences bind the c-terminal domain of integrase protein with different affinities that correlate with transposon insertion frequency. | the conjugative transposon tn916 inserts with widely different frequencies into a variety of target sites with related nucleotide sequences. the binding of chimeric proteins, consisting of maltose-binding protein fused to tn916 integrase, to three different target sequences for tn916 was examined by dnase i protection experiments. the c-terminal dna binding domain of the tn916 integrase protein was shown to protect approximately 40 bp, spanning target sites in the orfa and cat genes of the plasm ... | 1995 | 7721684 |
| identification and characterization of an enterococcus faecalis plasmid pad1-encoded stability determinant which produces two small rna molecules necessary for its function. | a determinant, designated par, essential for stable maintenance for an autonomously replicating fragment of the enterococcus faecalis plasmid pad1, was identified by transposon mutagenesis, and its dna sequence was determined. the position of flanking transposon inserts with no effect on stability indicates that par is encoded on no more than approximately 720 bp of dna. this region contains no large open reading frames (> 62 amino acids) but does contain a number of direct and inverted repeats ... | 1994 | 7531349 |
| regulation of tryptophan operon expression by attenuation in cell-free extracts of escherichia coli. | expression of the tryptophan (trp) operon of escherichia coli was shown to be regulated by attenuation in an in vitro dna-dependent protein-synthesizing system. in extracts prepared from a temperature-sensitive tryptophanyl-trna synthetase mutant, plasmid-directed trpe enzyme synthesis was inhibited 2- to 3-fold by addition of purified wild type tryptophanyl-trna synthetase. when the extract used from a strain bearing a trptts mutation that reduces charging of trnatrp in vivo, a 2- to 3-fold inc ... | 1982 | 7047528 |
| mu-lac insertion-directed mutagenesis in a pectate lyase gene of erwinia chrysanthemi. | the pelc gene, which encodes one of the five major pectate lyase (pl) isoenzymes in erwinia chrysanthemi 3937, designated plc, was subcloned from a hybrid lambda phage into a pbr322 derivative and mutagenized with a mini-mu-lacz transposable element able to form fusions to the lacz gene. one plasmid (pad1) which had an inactivated pelc gene and a lac+ phenotype was selected in escherichia coli. this plasmid was introduced into erwinia chrysanthemi, and the pelc::mini-mu insertion was substituted ... | 1985 | 2993251 |
| sex pheromones and plasmid transfer in enterococcus faecalis. | plasmid-free enterococcus faecalis excrete peptides (sex pheromones) which specifically induce a mating response in strains harboring certain conjugative plasmids. the response is characterized by the synthesis of a "fuzzy" surface material, visible by electron microscopy, which is believed to facilitate the aggregation of donors and recipients. transconjugants which receive a specific plasmid shut down the production of endogenous pheromone; however, they continue to produce pheromones specific ... | 1989 | 2550976 |
| regulation of the pad1 sex pheromone response in enterococcus faecalis: effects of host strain and traa, trab, and c region mutants on expression of an e region pheromone-inducible lacz fusion. | pheromone-induced conjugal transfer of the hemolysin-bacteriocin plasmid pad1 of enterococcus faecalis is regulated by a cluster of determinants designated traa, trab, and regions c and e. the e region is believed to include a positive regulator that controls many structural genes related to conjugation. the pheromone-inducible tn917-lac fusion nr5, located in the e region, is regulated by the products of traa, trab, and the c region. to more closely examine the effects of these genes on the ind ... | 1990 | 2158976 |
| nucleotide sequence of the sex pheromone inhibitor (iad1) determinant of enterococcus faecalis conjugative plasmid pad1. | the determinant for the peptide sex pheromone inhibitor iad1 (iad) on the hemolysin/bacteriocin plasmid pad1 of enterococcus faecalis was sequenced. the sequence reveals a 22-amino-acid precursor with the carboxyl-terminal 8 residues corresponding to iad1. it appears that iad1 is a component of its own signal sequence. | 1990 | 2128961 |
| molecular and genetic analysis of a region of plasmid pcf10 containing positive control genes and structural genes encoding surface proteins involved in pheromone-inducible conjugation in enterococcus faecalis. | exposure of enterococcus faecalis cells carrying the tetracycline resistance plasmid pcf10 to the heptapeptide pheromone ccf10 results in an increase in conjugal transfer frequency by as much as 10(6)-fold. pheromone-induced donor cells also express at least two plasmid-encoded surface proteins, the 130-kda sec 10 protein, which is involved in surface exclusion, and the 150-kda asc10 protein, which has been associated with the formation of mating aggregates. previous subcloning and transposon mu ... | 1991 | 1938961 |
| a phase variation event that activates conjugation functions encoded by the enterococcus faecalis plasmid pad1. | enterococcus faecalis cells carrying the conjugative plasmid pad1 undergo several related changes when induced by the sex pheromone cad1. included are the production of novel surface proteins, the formation of cellular aggregates in broth cultures, the ability to transfer the plasmid at high frequency in broth matings, and the change from a soft to a "dry" colony morphology. spontaneous, constitutively dry colony (dryc) variants of e. faecalis (pad1) were found to arise at a frequency of 10(-4)- ... | 1991 | 1661426 |
| transcriptional control of sex-pheromone-inducible genes on plasmid pad1 of enterococcus faecalis and sequence analysis of a third structural gene for (ppd1-encoded) aggregation substance. | the expression of several neighbouring genes on plasmid pad1 that are necessary for conjugation depend on induction with sex pheromone cad1. analyses of transcripts by northern blot hybridization demonstrated that the genes sea1 (encoding surface exclusion protein) and asa1 (encoding aggregation substance) are transcribed independently. both genes are organized in different operons together with neighbouring open reading frames of unknown function. several transcripts could be identified for sea ... | 1992 | 1640831 |
| sex pheromone plasmid pad1-encoded surface exclusion protein of enterococcus faecalis. | during conjugative transfer of sex pheromone plasmids of enterococcus faecalis a so-called surface exclusion protein reduces the frequency with which these plasmids are transferred to cells already possessing the same plasmid. we report here the dna sequence of a 3.8 kb fragment of the sex pheromone plasmid pad1 containing the structural gene sea1 for surface exclusion protein and a small open reading frame (orf) upstream of sea1. surface exclusion protein sea1 was found to be highly homologous ... | 1992 | 1603060 |
| regulation of the pad1-encoded sex pheromone response in enterococcus faecalis: nucleotide sequence analysis of traa. | the enterococcus faecalis plasmid pad1 conjugatively transfers in response to a sex pheromone, cad1, excreted by potential recipient cells. a key determinant responsible for regulation of pad1 transfer is traa, which encodes a negative regulator also believed to function in signal sensing. in this study, we analyzed the nucleotide sequence and transcription of traa. a protein of 319 amino acids with a molecular weight of 37,856 was inferred and found to exhibit limited homology with several dna- ... | 1992 | 1312529 |
| hyperhemolytic phenomena associated with insertions of tn916 into the hemolysin determinant of enterococcus faecalis plasmid pad1. | members of the tn916 family of conjugative transposons are able to insert themselves into enterococcus faecalis hemolysin/bacteriocin plasmid pad1 (and related elements) in such a way as to generate hyperexpression of the hemolysin/bacteriocin. to examine this phenomenon in more detail, e. faecalis (pad1::tn916) derivatives defective or altered in hemolysin expression were isolated and characterized with respect to production of the l (lytic) or a (activator) component (also known as cyla) and t ... | 1992 | 1312528 |
| pheromone-responsive conjugative vancomycin resistance plasmids in enterococcus faecalis isolates from humans and chicken feces. | the drug resistances and plasmid contents of a total of 85 vancomycin-resistant enterococcus (vre) strains that had been isolated in korea were examined. fifty-four of the strains originated from samples of chicken feces, and 31 were isolated from hospital patients in korea. enterococcus faecalis kv1 and kv2, which had been isolated from a patient and a sample of chicken feces, respectively, were found to carry the plasmids psl1 and psl2, respectively. the plasmids transferred resistances to van ... | 2006 | 17021204 |
| drug resistance of enterococcus faecium clinical isolates and the conjugative transfer of gentamicin and erythromycin resistance traits. | drug resistance and the transferability of resistance were examined in 218 enterococcus faecium clinical isolates obtained from in-patients of a japanese university hospital between 1990 and 1999. one hundred and sixty one isolates (73.9%) were drug-resistant and 127 (58.2%) isolates were resistant to two or more drugs. vancomycin resistant e. faecium (vre) was not isolated. the transferability of drug-resistance to an e. faecium strain was examined by broth or filter mating. six (12.5%) of the ... | 2005 | 15686834 |
| antisense rna regulation by stable complex formation in the enterococcus faecalis plasmid pad1 par addiction system. | the par stability determinant, encoded by the enterococcus faecalis plasmid pad1, is the only antisense rna regulated postsegregational killing system identified in gram-positive bacteria. because of the unique organization of the par locus, the par antisense rna, rna ii, binds to its target, rna i, at relatively small, interspersed regions of complementarity. the results of this study suggest that, rather than targeting the antisense bound message for rapid degradation, as occurs in most other ... | 2004 | 15375120 |
| enterococcus faecalis plasmid pad1-encoded fst toxin affects membrane permeability and alters cellular responses to lantibiotics. | fst is a peptide toxin encoded by the par toxin-antitoxin stability determinant of enterococcus faecalis plasmid pad1. intracellular overproduction of fst resulted in simultaneous inhibition of all cellular macromolecular synthesis concomitant with cell growth inhibition and compromised the integrity of the cell membrane. cells did not lyse or noticeably leak intracellular contents but had specific defects in chromosome partitioning and cell division. extracellular addition of synthetic fst had ... | 2003 | 12644486 |
| properties of enterococcus faecalis plasmid pad1, a member of a widely disseminated family of pheromone-responding, conjugative, virulence elements encoding cytolysin. | the 60-kb pad1 represents a large and widely disseminated family of conjugative, pheromone-responding, virulence plasmids commonly found in clinical isolates of enterococcus faecalis. it encodes a hemolysin/bacteriocin (cytolysin) shown to contribute to virulence in animal models, and the related bacteriocin is active against a wide variety of gram-positive bacteria. this review summarizes what is currently known about the molecular biology of pad1, including aspects of its cytolytic, uv-resista ... | 2007 | 17590438 |
| characterization of an active partition system for the enterococcus faecalis pheromone-responding plasmid pad1. | enterococcus faecalis plasmid pad1 is a 60-kb conjugative, low-copy-number plasmid that encodes a mating response to the peptide sex pheromone cad1 and a cytolytic exotoxin that contributes to virulence. although aspects of conjugation have been studied extensively, relatively little is known about the control of pad1 maintenance. previous work on pad1 identified a 5-kb region of dna sufficient to support replication, copy control, and stable inheritance (k. e. weaver, d. b. clewell, and f. an, ... | 2007 | 17905984 |
| translational regulation by an intramolecular stem-loop is required for intermolecular rna regulation of the par addiction module. | the par stability determinant of enterococcus faecalis plasmid pad1 is the only antisense rna-regulated addiction module identified to date in gram-positive bacteria. par encodes two small, convergently transcribed rnas, designated rna i and rna ii, that function as the toxin (fst)-encoding and antitoxin components, respectively. previous work showed that structures at the 5' end of rna i are important in regulating its translation. the work presented here reveals that a stem-loop sequestering t ... | 2008 | 18641135 |
| structural analysis of the anti-q-qs interaction: rna-mediated regulation of e. faecalis plasmid pcf10 conjugation. | conjugation of the e. faecalis plasmid pcf10 is triggered in response to peptide sex pheromone ccf10 produced by potential recipients. regulation of this response is complex and multi-layered and includes a small regulatory rna, anti-q that participates in a termination/antitermination decision controlling transcription of the conjugation structural genes. in this study, the secondary structure of the anti-q transcript and its sites of interaction with its target, qs, were determined. the primar ... | 2010 | 20332003 |
| solution structure and membrane binding of the toxin fst of the par addiction module. | the par toxin-antitoxin system is required for the stable inheritance of the plasmid pad1 in its native host enterococcus faecalis. it codes for the toxin fst and a small antisense rna which inhibits translation of toxin mrna, and it is the only known antisense regulated toxin-antitoxin system in gram-positive bacteria. this study presents the structure of the par toxin fst, the first atomic resolution structure of a component of an antisense regulated toxin-antitoxin system. the mode of membran ... | 2010 | 20677831 |