Publications

identification of int and attp on the genome of lactococcal bacteriophage tuc2009 and their use for site-specific plasmid integration in the chromosome of tuc2009-resistant lactococcus lactis mg1363.	the dna sequence of the int-attp region of the small-isometric-headed lactococcal bacteriophage tuc2009 is presented. in this region, an open reading frame, int, which potentially encodes a protein of 374 amino acids, representing the tuc2009 integrase, was identified. the nucleotide sequence of the bacteriophage attachment site, attp, and the sequences of attb, attl, and attr in the lysogenic host lactococcus lactis subsp. cremoris uc509 were determined. a sequence almost identical to the uc509 ...	1994	8074513
purification and properties of the alpha-acetolactate decarboxylase from lactococcus lactis subsp. lactis ncdo 2118.	alpha-acetolactate decarboxylase from lactococcus lactis subsp. lactis ncdo 2118 was expressed at low levels in cell extracts and was also unstable. the purification was carried out from e. coli in which the enzyme was expressed 36-fold higher. the specific activity was 24-fold enhanced after purification. the main characteristics of alpha-acetolactate decarboxylase were: (i) activation by the three branched chain amino acids leucine, valine and isoleucine; (ii) allosteric properties displayed i ...	1994	8076701
the immune response to lactococcus lactis: implications for its use as a vaccine delivery vehicle.	the development of natural antibodies to lactococcus lactis in three inbred strains of mice and the effect of inoculating l. lactis into these mice has been investigated. all animals developed detectable levels of natural (systemic and secretory) anti-lactococcal antibodies. systemic anti-lactococcal antibodies were principally igg in young mice. an increase in anti-lactococcal igm occurred in all older animals. inoculation of l. lactis strains mg1820 or mg1363 by the oral and parenteral routes ...	1994	8076800
genetic analysis of the minimal replicon of the lactococcus lactis subsp. lactis biovar diacetylactis citrate plasmid.	using a combination of mutagenesis with the transposon gamma delta and polymerase chain reaction subcloning, the essential elements of the replication region of the lactococcus lactis subsp. lactis biovar diacetylactis citrate plasmid have been identified. an open reading frame, coding for a protein with homology to rep proteins from other lactococcus plasmids, is essential. this protein is trans-acting and could not be replaced by the rep protein from another lactococcus plasmid. a second open ...	1994	8078463
the majority of lactococcal plasmids carry a highly related replicon.	dna sequence analysis and southern hybridizations, together with complementation experiments, were used to study relationships between lactococcal plasmid replicons. pwvo2, pwvo4 and pwvo5, which co-exist in lactococcus lactis subsp. cremoris wg2, and pil7 (isolated from another strain) all contained a functional replication region which appeared to be very similar to that of some known lactococcal plasmids. they contain a gene encoding a highly conserved repb protein (60-80% amino acid identity ...	1994	8081493
cloning, sequencing and comparison of three lactococcal l-lactate dehydrogenase genes.	the conversion of pyruvate to lactate is a key feature of lactococcal strains. the enzyme which facilitates this conversion, l-lactate dehydrogenase (ldh), and the gene which encodes it (idh), are therefore of great significance. this paper presents the cloning and dna sequence analysis of three further lactococcal genes which are of key importance in the genetic manipulation of commercial starter strains. the idh gene from lactococcus lactis subsp. lactis biovar diacetylactis bu2-60 has been is ...	1994	8081494
membrane-associated proteins encoded by the nisin gene cluster may function as a receptor for the lantibiotic carnocin ui49.	carnocin ui49, a lantibiotic produced by carnobacterium piscicola shows bactericidal activity against many lactic acid bacteria. this paper describes the results of a study on the mode of action of carnocin ui49. it has previously been observed that nisin-producing lactococcus lactis subsp. lactis strains are at least 10-fold more sensitive to carnocin ui49 relative to other lactic acid bacteria. addition of carnocin ui49 to cells of l. lactis subsp. lactis nz9700 resulted in a dissipation of th ...	1994	8081505
bglr protein, which belongs to the bglg family of transcriptional antiterminators, is involved in beta-glucoside utilization in lactococcus lactis.	a fragment of the lactococcus lactis chromosome containing an open reading frame of 265 codons, denoted bglr, has been characterized. the polypeptide encoded by bglr shares 36 to 30% sequence identity with a family of regulatory proteins including arbg from erwinia chrysanthemi, bglg from escherichia coli, and sact and sacy from bacillus subtilis. these regulatory proteins are involved in positive control of the utilization of different sugars by transcription antitermination. for some of these ...	1994	8083160
monoclonal antibody-based enzyme immunoassay for pediocins of pediococcus acidilactici.	monoclonal antibody (mab) r2-ar against pediocin rs2 was developed. mice were immunized for 12 weeks with pediocin rs2 conjugated to a polyacrylamide gel. two hybridoma fusions yielded an mab that in western blots (immunoblots) reacted only with pediocins rs2 and ach (3 kda) from pediococcus acidilactici rs2 and h, respectively, and did not react with any other bacteriocin, including sakacin a from lactobacillus sake lb 706, leuconocin lcm1 from leuconostoc carnosum lm1, nisin from lactococcus l ...	1994	8085814
production of chymosin for the dairy industry by recombinant dna technology.	the increasing world production of cheese, coupled with a decline in the number of slaughtered calves, has stimulated a search for alternative sources of chymosin. this article briefly reviews microbial alternatives to chymosin and discusses chymosins produced using recombinant dna technology. recombinant chymosin represents one of the first successful applications of recombinant dna technology in the food industry.	1994	7764615
influence of dilution rate and cell immobilization on plasmid stability during continuous cultures of recombinant strains of lactococcus lactis subsp. lactis.	the influence of dilution rate and cell immobilization on plasmid stability in recombinant strains of lactococcus lactis subsp. lactis was investigated during continuous cultures. the studied strains, l. lactis il2682 and il2683, contained plasmids pil9 (lac+), pil205 (cmr) and plasmids pil252 (low copy number) and pil253 (high copy number), respectively, that conferred resistance to erythromycin. plasmid pil205 was remarkably stable. dilution rate did not affect the rate of loss of plasmids pil ...	1994	7764746
rapid isolation and purification of lactococcal bacteriophage dna without the use of caesium chloride gradients.	intact bacteriophage of lactococcus lactis were recovered from small volumes of lysate by centrifugation at 15,000 g without precipitation with polyethylene glycol and sodium chloride, or ultracentrifugation in a caesium chloride gradient. dna was then extracted and purified by standard protocols. this dna was readily digested with restriction endonucleases and used successfully in hybridization experiments.	1994	7764812
action of a cell-envelope proteinase (cepiii-type) from lactococcus lactis subsp. cremoris am1 on bovine kappa-casein.	the specificity of the cell-envelope proteinase (cepiii-type) from lactococcus lactis subsp. cremoris am1 in its action on bovine kappa-casein was studied. a 4-h digest (ph 6.2, 15 degrees c) of kappa-casein was made with the purified proteinase. the ph-4.6 soluble fraction, representing more than 95% of the whole hydrolysate, was ultrafiltered to obtain a high-molecular-mass (hmm) and a low-molecular-mass (lmm) fraction, which were separately further purified by electrophoretic and chromatograp ...	1994	7765163
a novel approach for high level production of a recombinant human parathyroid hormone fragment in escherichia coli.	we describe a novel approach to the production in e. coli of a peptide fragment derived from the human parathyroid hormone (hpth). the first 38 amino acids of hpth were fused at the amino terminus to a derivative of the bacteriophage t4-encoded gp55 protein, and were expressed in the e. coli cytoplasm in inclusion bodies at levels exceeding 50% of the total cell protein. solubilization and subsequent incubation of the inclusion bodies in dilute hydrochloric acid facilitated the cleavage of an ac ...	1994	7765406
expression of lactobacillus casei atcc 393 beta-galactosidase encoded by plasmid plz15 in lactococcus lactis cnrz 1123.	lactococcus lactis subsp. lactis cnrz 1123, a lac- derivative of cnrz 1122 was transformed by electroporation with the lactobacillus casei atcc 393 plasmid plz15, which bears a beta-galactosidase gene. the transformants expressed a constitutive beta-galactosidase activity at a higher level than in lact. casei, and in the cell-free extract two additional protein bands were detected by sds-page which could correspond to lactose metabolism enzymes. both plasmid and beta-gal activity were stable in ...	1994	7765447
cloning and nucleotide sequencing of l-lactate dehydrogenase gene from streptococcus thermophilus m-192.	the gene encoding l-lactate dehydrogenase (ldh) was cloned from an industrial dairy strain of streptococcus thermophilus m-192 using a synthetic oligonucleotide probe based on the n-terminal amino acid sequence of the purified enzyme, and its nucleotide sequence was determined. the enzyme was deduced to have 328 amino acid residues with a molecular weight of 35,428 and found to have high sequence similarity to ldhs from other lactic acid bacteria (89.0% to streptococcus mutans, 76.3% to lactococ ...	1994	7765475
expression of a chitinase gene from serratia marcescens in lactococcus lactis and lactobacillus plantarum.	a chitinase gene from the gram-negative bacterium serratia marcescens bjl200 was cloned in lactococcus lactis subsp. lactis mg1363 and in the silage inoculum strain lactobacillus plantarum e19b. the chitinase gene was expressed as an active enzyme at a low level in lactococcus lactis, when cloned in the same transcriptional orientation as the gene specifying the replication protein of the vector pil253. using the expression vectors pmg36e and pgkv259 with lactococcal promoter fragments p32 and p ...	1994	7765812
utilization of cheddar cheese containing nisin as an antimicrobial agent in other foods.	cheddar cheese made with nisin-producing lactococci contained between 400 and 1200 iu of nisin per gram of cheese. cultures used were lactococcus lactis ssp. cremoris js102, a nisin-producing transconjugant developed in the laboratories of dr. l.l. mckay and lactococcus lactis ssp. lactis ncdo 1404 obtained from the national collection of food bacteria, reading, england. pasteurized process cheese spreads with 53% and 60% moisture and 0, 301 and 387 iu nisin/g were manufactured and inoculated wi ...	1994	7703016
scanning electron microscopy of target cells and molecular weight determination of a bacteriocin produced by lactococcus lactis d53.	a bacteriocin, lactococcin d53, from lactococcus lactis strain d53 was partially purified by precipitation with ammonium sulfate and dialysis against deionized water, at which time it precipitated from solution. a native molecular weight was determined by gel filtration, where bacteriocin was detected in two fractions which were measured at 104 and 6.7 kda. a molecular weight of 7.0 kda under denaturing conditions was determined by tricine-sds-polyacrylamide gel electrophoresis. the molecular we ...	1994	7703022
cloning of promoter-like sequences from lactobacillus paracasei subsp. paracasei cg11 and their expression in escherichia coli, lactococcus lactis, and lactobacillus reuteri.	fragments of chromosomal dna from lactobacillus paracasei subsp. paracasei cg11 (formerly lactobacillus casei cg11) capable of functioning as promoters were isolated using the broad host range, promoter-probe vector pgkv210. five such fragments designated p61, p79, p80, p116, and p144 were completely sequenced and analyzed. fragment p61 had the highest transcriptional efficiency in escherichia coli and lactobacillus reuteri whereas p80 was the most active in lactococcus lactis. in general, the o ...	1994	7704831
biochemical and genetic characterization of pepf, an oligopeptidase from lactococcus lactis.	lactococcus lactis possesses a complex proteolytic system which is essential for its growth in milk. we characterized one of the peptidases of this system, oligopeptidase pepf, together with its structural gene. pepf hydrolyzed peptides containing between 7 and 17 amino acids with a rather wide specificity. it was purified to homogeneity. the n-terminal sequences of pepf and of peptides resulting from tryptic digestion of pepf were determined and used to design degenerate oligonucleotides which ...	1994	7798200
genetic analysis of regions of the lactococcus lactis subsp. lactis plasmid prs01 involved in conjugative transfer.	the genes responsible for conjugative transfer of the 48.4-kb lactococcus lactis subsp. lactis ml3 plasmid prs01 were localized by insertional mutagenesis. integration of the is946-containing plasmid ptrk28 into prs01 generated a pool of stable cointegrates, including a number of plasmids altered in conjugative proficiency. mapping of ptrk28 insertions and phenotypic analysis of cointegrate plasmids identified four distinct regions (tra1, tra2, tra3, and tra4) involved in prs01 conjugative trans ...	1994	7811081
mosaic structure of large regions of the lactococcus lactis subsp. cremoris chromosome.	lactococcus lactis subsp. lactis and lactococcus lactis subsp. cremoris are closely related phenotypically and genetically. here we report that certain regions of their chromosomes diverge considerably more than others. conserved regions differ by less than 20%, whilst variable regions differ by more than 60%. this mosaic structure may have arisen by horizontal gene transfer from distantly related bacteria since in a particular region of the l. lactis subsp. cremoris chromosome the g+c content a ...	1994	7812446
absence of cholic acid 7 alpha-dehydroxylase activity in the strains of lactobacillus and bifidobacterium.	to investigate the presence of 7 alpha-dehydroxylase activity on bile acids in the bacterial strains of fermented milk products, 46 strains of lactobacillus casei, lactobacillus paracasei, lactobacillus rhamnosus, lactobacillus acidophilus, lactobacillus gasseri, bifidobacterium adolescentis, bifidobacterium bifidum, bifidobacterium breve, bifidobacterium infantis, bifidobacterium longum, lactococcus lactis spp. lactis, and streptococcus salivarius spp. thermophilus were tested for their ability ...	1994	7814703
the pot family of transport proteins.		1994	7817396
purification and characterization of a general aminopeptidase (st-pepn) from streptococcus salivarius ssp. thermophilus cnrz 302.	a general aminopeptidase (st-pepn) was purified from an intracellular extract of streptococcus salivarius ssp. thermophilus cnrz 302 by ion-exchange chromatography and hydrophobic interaction chromatography. gel electrophoresis of the purified enzyme in denaturing or nondenaturating conditions showed a single protein band. the enzyme is a monomer with a molecular mass of 97 kda. its activity is maximal at ph 7 and 36 degrees c and is completely abolished by cucl2 and zncl2. the enzyme is strongl ...	1994	7836577
[the dental pulp reaction to microbial action in different methods of treating the carious cavity].	under study were the effects of bacterial stimulation of prepared dentin on dental pulp. traditional method of drug treatment of prepared cavity with alcohol and either was compared with methods reducing dentin permeability making use of calcium hydroxide, potassium nitrate, and calcium oxalate. inflammatory reaction of the pulp was more pronounced after traditional treatment. reduction of dentin permeability with agents blocking dentin tubes reduced the severity of inflammatory reaction.	1994	7846716
cloning and nucleotide sequence analysis of the lactobacillus delbrueckii ssp. lactis dsm7290 cysteine aminopeptidase gene pepc.	a genomic library of lactobacillus delbrueckii ssp. lactis dsm7290 in the low copy number vector plg339, was screened for the presence of peptidase genes. using the chromogenic substrate gly-ala-beta-naphthylamide, which is not a substrate for any of the recently cloned peptidases of dsm7290, and the multiple peptidase deficient escherichia coli strain cm89, allowed the isolation of clones, which contained the equivalent hydrolytic activity. to identify genes encoding the conserved catalytic act ...	1994	7851736
regulation of 2-deoxyglucose phosphate accumulation in lactococcus lactis vesicles by metabolite-activated, atp-dependent phosphorylation of serine-46 in hpr of the phosphotransferase system.	lactococcus lactis takes up glucose and the nonmetabolizable glucose analogue 2-deoxyglucose (2dg) via the phosphotransferase system and extrudes the accumulated sugar phosphates in a process apparently dependent on a cytoplasmic sugar-phosphate phosphatase. uptake of 2dg into l. lactis vesicles was shown to be dependent on an energy source, effectively provided by intravesicular phosphoenolpyruvate (pep). 2dg phosphate (2dg-p) accumulation in these vesicles was not inhibited, and preaccumulated ...	1994	7881559
sequence of the afg3 gene encoding a new member of the ftsh/yme1/tma subfamily of the aaa-protein family.	a nuclear gene from saccharomyces cerevisiae was cloned by genetic complementation of a temperature-sensitive respiratory-deficient mutant. dna sequence analysis reveals that it encodes a protein with homology to yme1, ftsh and tma, proteins which belong to the aaa-protein family (atpases associated with diverse cellular activities). the members of this family are involved in very different biological processes. yme1p, a yeast mitochondrial protein, affects the rate of dna escape from mitochondr ...	1994	7900428
xaa-pro-dipeptidyl-aminopeptidase from lactococcus lactis catalyses kinetically controlled synthesis of peptide bonds involving proline.	xaa-pro-dipeptidyl-aminopeptidase (ec 3.4.14.5) from lactococcus lactis (pepx) was used, for the first time, as a catalyst in kinetically controlled synthesis of peptide bonds involving proline. pepx had amidase and esterase activities in addition to peptidase activity. thus amide and ester derivatives of x-pro peptides could be employed as acyl donors. pepx showed a broad specificity for the residue in position p'1, accepting a large variety of amino acid amides, esters, peptides as well as fre ...	1994	7917062
expression, purification, and characterization of thymidylate synthase from lactococcus lactis.	the thymidylate synthase (ts) gene from lactococcus lactis has been highly expressed in escherichia coli. the ts protein was purified by sequential chromatography on q-sepharose and phenyl-sepharose. six grams of cell pellet yielded 140 mg of homogeneous ts. ts is a highly conserved enzyme, and several of the conserved amino acid residues that have been implicated in catalytic function are altered in l. lactis ts. by use of a 3-dimensional homology model, we have predicted covariant changes that ...	1994	7920258
study of gene transfer in vitro and in the digestive tract of gnotobiotic mice from lactococcus lactis strains to various strains belonging to human intestinal flora.	the use of genetically modified organisms (gmo) in dairy products requires evaluation of the dna transfer capacity from such organisms among the human intestinal microflora. thus, both in vitro and in vivo [in the digestive tract (dt) of mice] transfer from lactococcus lactis donor strains of the conjugative plasmid pil205 (cmr) and the non-conjugative plasmid pil253 (emr) to: (1) recipient strains isolated from human faecal flora bacteroides sp., bifidobacterium sp., peptostreptococcus sp. (str ...	1994	7921350
cloning, molecular characterization, and expression of the genes encoding the lytic functions of lactococcal bacteriophage phi lc3: a dual lysis system of modular design.	the genes encoding the lysis proteins of lactococcus lactis bacteriophage phi lc3 were cloned, sequenced, and expressed in escherichia coli. the phi lc3 lysis genes, lysa and lysb, encode a membrane-disrupting protein (lysa) of 88 amino acids, and a cell wall degrading protein (lysb) of 429 amino acids, which shares significant sequence similarity with lysins from the streptococcus pneumoniae phages cp-1, cp-7, and cp-9, and lactobacillus delbrueckii phage mv1. both lysa and lysb function in e. ...	1994	7922887
gene cloning and characterization of pepc, a cysteine aminopeptidase from streptococcus thermophilus, with sequence similarity to the eucaryotic bleomycin hydrolase.	streptococcus thermophilus cnrz 302 contains at least three general aminopeptidases able to hydrolyze phe-beta-naphthylamide substrate. the gene encoding one of these aminopeptidases was cloned from a total dna library of s. thermophilus cnrz 302 constructed in escherichia coli tg1 using pbluescript plasmid. the wild-type tg1 strain, although not deficient in aminopeptidase activity, is unable to hydrolyze the substrate phe-beta-naphthylamide, and thus the library could be screened with an enzym ...	1994	7925365
characterization and expression of the lactobacillus helveticus pepc gene encoding a general aminopeptidase.	an aminopeptidase c gene (pepc) was detected by nucleic acid hybridization from an industrially important lactobacillus helveticus strain. three hybridization positive clones were isolated from a gene library of this l. helveticus strain, and one of them was characterized in more detail. deletion mapping localized the hybridization positivity into a 2.8-kb fragment, which also encoded aminopeptidase activity. this fragment was sequenced and two open reading frames (orf1 and 2) of 1347 and 840 ba ...	1994	7925424
confirmation of the existence of a third family among peptidyl-prolyl cis/trans isomerases. amino acid sequence and recombinant production of parvulin.	in addition to the major cyclophilin-like peptidyl-prolyl cis/trans isomerases (ppiases) of escherichia coli an enzyme of very low relative molecular mass (10.1 kda) was discovered in this organism which gave first indication of the existence of a novel family in this enzyme class [1994, febs lett. 343, 65-69]. in the present report we describe the chemically determined amino acid sequence of four peptides derived from the 10.1 kda protein by the treatment with either cyanogen bromide or endopro ...	1994	7925971
evidence for a large dispensable segment in the subtilisin-like catalytic domain of the lactococcus lactis cell-envelope proteinase.	the lactococcus lactis sk11 cell-envelope proteinase contains various inserts, located in external loops of the catalytic domain compared with related subtilisins. in this study, protein engineering was employed to determine the function of the largest loop insertion (residues 238-388) relative to the subtilisin structure. by site-directed mutagenesis we have deleted the fragment of the proteinase gene encoding these 151 residues and analyzed the mutant delta 238-388 proteinase for activity, (au ...	1994	7528919
[the immunostimulating action of lactobacteria on the cytotoxicity of natural killer cells and interferon production].		1994	7533464
mode of action of lcia, the lactococcin a immunity protein.	monoclonal antibodies were raised against a fusion between the escherichia coli maltose-binding protein and lcia, the immunity protein that protects lactococcus lactis against the effects of the bacteriocin lactococcin a. one of the antibodies directed against the lcia moiety of the fusion protein was used to locate the immunity protein in the l. lactis producer cell. lcia was present in the cytosolic, the membrane-associated, and the membrane fractions in roughly equal amounts, irrespective of ...	1994	7533883
phenotypic consequences of altering the copy number of abia, a gene responsible for aborting bacteriophage infections in lactococcus lactis.	the abia gene (formerly hsp) encodes an abortive phage infection mechanism which inhibits phage dna replication. to analyze the effects of varying the abia gene dosage on bacteriophage resistance in lactococcus lactis, various genetic constructions were made. an is946-based integration vector, ptrk75, was used to integrate a single copy of abia into the chromosomes of two lactococcal strains, mg1363 and nck203. in both strains, a single copy of abia did not confer any significant phage resistanc ...	1994	16349225
galactose expulsion during lactose metabolism in lactococcus lactis subsp. cremoris fd1 due to dephosphorylation of intracellular galactose 6-phosphate.	in lactococcus lactis subsp. cremoris fd1, galactose and lactose are both transported and phosphorylated by phosphotransferase systems. lactose 6-phosphate (lactose-6p) is hydrolyzed intracellularly to galactose-6p and glucose. glucose enters glycolysis as glucose-6p, whereas galactose-6p is metabolized via the tagatose-6p pathway and enters glycolysis at the tagatose diphosphate and fructose diphosphate pool. galactose would therefore be a gluconeogenic sugar in l. lactis subsp. cremoris fd1, b ...	1994	16349233
c nuclear magnetic resonance studies of citrate and glucose cometabolism by lactococcus lactis.	c nuclear magnetic resonance (c-nmr) was used to investigate the metabolism of citrate plus glucose and pyruvate plus glucose by nongrowing cells of lactococcus lactis subsp. lactis 19b under anaerobic conditions. the metabolism of citrate plus glucose during growth was also monitored directly by in vivo nmr. although pyruvate is a common intermediate metabolite in the metabolic pathways of both citrate and glucose, the origin of the carbon atoms in the fermentation products was determined by us ...	1994	16349269
evolution of a lytic bacteriophage via dna acquisition from the lactococcus lactis chromosome.	we discovered a phage-host interaction in which the lytic phage ul36, in response to pressure exerted by an abortive phage resistance mechanism, acquired a large dna fragment from the chromosome of lactococcus lactis nck203 to form a new phage, ul37. phage ul37 was characterized at morphological, phenotypic, and genotypic levels and was found to be a member of the p335 species. although it exhibits a high level of dna homology with ul36, phage ul37 is resistant to the abortive mechanism and has ...	1994	16349277
mode of action of nisin z against listeria monocytogenes scott a grown at high and low temperatures.	nisin z, a natural nisin variant, was recently isolated from lactococcus lactis subspecies lactis nizo 22186. the gene for this lantibiotic, designated nisz, has been cloned, and its nucleotide sequence was found to be identical to that of the precursor nisin gene with the exception of a single mutation resulting in the substitution of asn-27 for his-27 in the mature polypeptide (j. w. m. mulders, i. j. boerrigter, h. s. rollema, r. j. siezen, and w. m. de vos, eur. j. biochem. 201:581-584, 1991 ...	1994	16349286
lactococcal bacteriophages require a host cell wall carbohydrate and a plasma membrane protein for adsorption and ejection of dna.	the mechanism of the initial steps of bacteriophage infection in lactococcus lactis subsp. lactis c2 was investigated by using phages c2, ml3, kh, l, h, 5, and 13. all seven phages adsorbed to the same sites on the host cell wall that are composed, in part, of rhamnose. this was suggested by rhamnose inhibition of phage adsorption to cells, competition between phage c2 and the other phages for adsorption to cells, and rhamnose inhibition of lysis of phage-inoculated cultures. the adsorption to t ...	1994	16349376
starvation-induced stress resistance in lactococcus lactis subsp. lactis il1403.	carbohydrate-starved cultures of lactococcus lactis subsp. lactis il1403 showed enhanced resistance to heat, ethanol, acid, osmotic, and oxidative stresses. this cross-protection seems to be established progressively during the transitional growth phase, with maximum resistance occurring when cells enter the stationary phase. chloramphenicol or rifamycin treatment does not abolish the development of a tolerant cell state but, on the contrary, seems to provoke this response in l. lactis subsp. la ...	1994	16349399
effect of genetically modifying the lactococcal proteolytic system on ripening and flavor development in cheddar cheese.	three batches of six cheddar cheeses were manufactured by using the following lactococcal strains: (i) uc317 as a control; (ii) jl3601, a proteinase-negative derivative of uc317 transformed with high-copy-number plasmid pci3601 containing the cloned proteinase gene complex from uc317; (iii) am312, a proteinase-negative derivative of uc317 transformed with plasmid pmg36enpr containing the neutral proteinase gene from bacillus subtilis; (iv) ac322, jl3601 transformed with pmg36enpr; (v) ac311, uc3 ...	1994	16349452
a starter culture rotation strategy incorporating paired restriction/ modification and abortive infection bacteriophage defenses in a single lactococcus lactis strain.	three derivatives of lactococcus lactis subsp. lactis nck203, each with a different pair of restriction/ modification (r/m) and abortive infection (abi) phage defense systems, were constructed and then rotated in repeated cycles of a milk starter culture activity test (sat). the rotation proceeded successfully through nine successive sats in the presence of phage and whey containing phage from previous cycles. lactococcus cultures were challenged with 2 small isometric-headed phages, (phi)31 and ...	1995	16534987
expression of a lactococcus lactis phage resistance mechanism by streptococcus thermophilus.	the 7.8-kb lactococcal plasmid psrq700 encodes the llaii restriction/modification system which recognizes and cleaves the sequence 3(prm1)-gatc-5(prm1). when the plasmid psrq700 is introduced into a phage-sensitive lactococcus lactis strain, strong phage resistance is conferred by the llaii system. in this report, we show that psrq700 cannot replicate in streptococcus thermophilus. however, if cloned into the vector pnz123, the native llaii system is expressed and strong phage resistance is conf ...	1995	16535064
purification and characterization of a dipeptidase from lactobacillus helveticus sbt 2171.	a metal-dependent dipeptidase was purified to homogeneity from a cell extract of lactobacillus helveticus sbt 2171 by fast protein liquid chromatography. the enzyme was purified 237-fold from the extract, with a yield of 1.8%. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme showed a single protein band with a molecular weight of 50,000. the dipeptidase hydrolyzes a range of only dipeptides. dipeptides containing proline, glutamic acid, and aspartic acid are not h ...	1995	16535128
cloning and sequencing of llaii restriction/modification genes from lactococcus lactis and relatedness of this system to the streptococcus pneumoniae dpnii system.	volume 61, no. 6, p. 2193-2202: the restriction/modification system designation "llaii" should read "lladchi" throughout the paper to conform to conventional nomenclature for such systems. [this corrects the article on p. 2193 in vol. 61.].	1995	16535138
purification and characterization of cystathionine (beta)-lyase from lactococcus lactis subsp. cremoris b78 and its possible role in flavor development in cheese.	an enzyme that degrades sulfur-containing amino acids was purified from lactococcus lactis subsp. cremoris b78; this strain was isolated from a mixed-strain, mesophilic starter culture used for the production of gouda cheese. the enzyme has features of a cystathionine (beta)-lyase (ec 4.4.1.8), a pyridoxal-5(prm1)-phosphate-dependent enzyme involved in the biosynthesis of methionine and catalyzing an (alpha),(beta)-elimination reaction. it is able to catalyze an (alpha),(gamma)-elimination react ...	1995	16535166
greenhouse and field evaluations of an autoselective system based on an essential thymidylate synthase gene for improved maintenance of plasmid vectors in modified rhizobium meliloti.	the stability of the thy autoselective system, based on an essential thymidylate synthase gene, for enhanced maintenance of plasmid vectors in rhizobium meliloti was evaluated in the greenhouse and with field-grown alfalfa. the thy autoselective system consists of a free-replicating, broad-host-range plasmid vector containing a copy of the thya gene from lactococcus lactis subsp. lactis and a spontaneous mutant of r. meliloti deficient in thymidylate synthase (thy(sup-)). under greenhouse condit ...	1995	16535168
modeling of continuous ph-stat stirred tank reactor with lactococcus lactis ssp. lactis bv. diacetylactis immobilized in calcium alginate gel beads.	a dynamic diffusion-reaction-growth model is proposed for the study of lactic fermentation, the bioconversion of citric acid, and cell release in an immobilized cell reactor [ph-stat continuous stirred tank-reactor (cstr)]. the model correctly simulates the onset of fermentation and colonization of the gel, followed by the steady state. external diffusion is nonlimiting and internal diffusion is limited by high cell densities at the periphery of the gel beads. lactose-citrate cometabolism in the ...	1995	18623436
powerful methods to establish chromosomal markers in lactococcus lactis: an analysis of pyrimidine salvage pathway mutants obtained by positive selections.	using different 5-fluoropyrimidine analogues, positive selection procedures for obtaining mutants blocked in pyrimidine and purine salvage genes of lactococcus lactis were established. strains lacking the following enzyme activities due to mutations in the corresponding genes were isolated: uracil phosphoribosyltransferase (upp), uridine/cytidine kinase (udk), pyrimidine nucleoside phosphorylase (pdp), cytidine/deoxycytidine deaminase (dd),thymidine kinase (tdk) and purine nucleoside phosphoryla ...	1995	20369419
detection of polygalacturonases and pectin esterases in lactic acid bacteria.	of 80 strains of lactic acid bacteria tested, only lactobacillus casei strains hnk10 and l1-8, lactobacillus plantarum lc5 and lactococcus lactis nn01 produced polygalacturonases (ec 3.2.1.) and/or pectin-esterases (ec 3.1.1.). crude extracellular extracts of strain l1-8 were able to clarify pectin.	1995	24414913
microbiology of pozol, a mexican fermented maize dough.	mexican fermented maize dough, pozol, including traditional banana leaf-wrapped samples and material in plastic bags, was purchased. all samples were ph 4.7 to 5.7 approx. 12 h after preparation, ph declining to 3.6 to 3.9 after 6 to 9 days storage at ambient temperature. these latter samples had dry matter contents of 31% to 48% (w/w), 0.35% to 0.75% titratable acidity as lactic acid and lactic acid bacteria as predominant microbial flora at about 10(8) c.f.u./ml. the lactic acid bacteria inclu ...	1995	24414915
effect of ragi and lxxx-lactate-producing cultures on enteric pathogens in a rice-based weaning food.	the use of the southeast-asian starter culture ragi in enhancing the safety of a rice-based model weaning food is described and compared with the use of diastatic malt extract. ragi was shown to be an effective saccharifying agent convenient for use in weaning-food preparation on a domestic scale. saccharification and fermentation with ragi alone produced some antimicrobial effect against the three enteric bacterial pathogens tested but this was much improved when ragi was used in conjunction wi ...	1995	24415015
the lactococcus lactis triosephosphate isomerase gene, tpi, is monocistronic.	triosephosphate isomerase (ec 5.3.1.1) from lactococcus lactis was purified to electrophoretic homogeneity. approximately 3 mg purified enzyme (specific activity 3300 u mg-1) was obtained from 70 g (wet wt) cells. in solution, triosephosphate isomerase (pi 4.0-4.4) was observed to exist as a homodimer (m(r) 57,000) of noncovalently linked subunits. the sequence of the first 37 amino acid residues from the nh2-terminus were determined by step-wise edman degradation. this sequence, and that of a r ...	1995	7534588
citrate utilization gene cluster of the lactococcus lactis biovar diacetylactis: organization and regulation of expression.	the transport of citrate in lactococcus lactis biovar diacetylactis is mediated by the citrate permease p. this polypeptide is encoded by the citp gene carried by plasmid pcit264. in this report, we characterize the citp transcript, identify a cluster of two genes cotranscribed with citp and describe their post-transcriptional regulation. the transcriptional promoter is located 1500 nucleotides upstream of the citp gene and the transcriptional terminator is positioned next to the 3'-end of this ...	1995	7535377
specific antibody-mediated detection of brochothrix thermosphacta in situ in british fresh sausage.	a rabbit polyclonal antibody-linked probe was developed which detected 76% of 800 food isolates of the spoilage bacterium brochothrix thermosphacta when cells were bound to nitrocellulose. in slide cross-reaction tests all six environmental isolates tested were stained but the type strain was not. the antibody did not cross-react with listeria grayi, l. monocytogenes, lactobacillus plantarum, lactococcus lactis, streptococcus mutans, bacillus cereus or b. subtilis. the antibody-linked probe dete ...	1995	7538105
characterization of prokaryotic mrnas by rt-pcr.		1995	7542457
enhancement of antigen-specific antibody production by extracellular slime products from slime-forming lactococcus lactis subspecies cremoris sbt 0495 in mice.	the effect of extracellular slime products (esp) produced by lactococcus lactis subspecies cremoris sbt 0495 on antigen specific antibody production was studied in mice. esp contained 48.5% protein, 15.4% neutral sugar, and 1.1% of phosphorus. the optimum dose of esp was between 100 to 500 micrograms per mouse. esp administered intraperitoneally (200 micrograms per mouse) enhanced the production of specific antibody in mice. these results indicate that esp may act as an adjuvant.	1995	7547146
transformation of lactococcus by electroporation.		1995	7550735
nucleotide sequence of the lantibiotic pep5 biosynthetic gene cluster and functional analysis of pepp and pepc. evidence for a role of pepc in thioether formation.	the biosynthesis of pep5, a lanthionine-containing antimicrobial peptide, is directed by the 20-kbp plasmid ped503. we identified a 7.9-kbp dna-fragment within this plasmid which covers the information for pep5 synthesis in the homologous host staphylococcus epidermidis 5 which has been cured of ped503. this fragment contained, in addition to the previously described structural gene pepa and the immunity gene pepi [reis, m., eschbach-bludau, m., iglesias-wind, m. i., kupke, t. & sahl, h.-g. (199 ...	1995	7556197
characterization of superoxide dismutase genes from gram-positive bacteria by polymerase chain reaction using degenerate primers.	an internal fragment representing approximately 85% of sod genes from seven gram-positive bacteria was amplified by using degenerate primers in a polymerase chain reaction assay. the dna sequences of sod polymerase chain reaction products from clostridium perfringens, enterococcus faecalis, enterococcus faecium, lactococcus lactis, staphylococcus aureus, streptococcus agalactiae, streptococcus pneumoniae, and streptococcus pyogenes were determined. comparisons of their deduced amino acid sequenc ...	1995	7557308
the cellular location and effect on nisin immunity of the nisi protein from lactococcus lactis n8 expressed in escherichia coli and l. lactis.	lactococcus lactis cells secreting the lantibiotic nisin, commercially used for food preservation, must protect their cell membrane against the pore-forming activity of extracellular nisin. the nisi gene product has been suggested to be a lipoprotein, which due to the location on the extracellular surface would be an ideal candidate for an immunity protein. in vivo labelling of nisi from l. lactis n8 expressed in escherichia coli proved that nisi is a lipoprotein. expression of nisi in the nisin ...	1995	7557313
construction of a streptococcus pyogenes reca mutant via insertional inactivation, and cloning and sequencing of the complete reca gene.	to facilitate future genetic studies with streptococcus pyogenes (sp), a reca mutant (rec11) was constructed using a streptococcal integration vector carrying a pcr-derived internal reca fragment. the insertion of the plasmid in the mutant chromosome was identified by southern hybridization. resistance to uv and the ability to accept linear dna transformation by rec11 were greatly decreased, confirming its reca phenotype. using the pcr-derived fragment as a probe, we cloned and sequenced the com ...	1995	7557418
a family of bacteriocin abc transporters carry out proteolytic processing of their substrates concomitant with export.	lantibiotic and non-lantibiotic bacteriocins are synthesized as precursor peptides containing n-terminal extensions (leader peptides) which are cleaved off during maturation. most non-lantibiotics and also some lantibiotics have leader peptides of the so-called double-glycine type. these leader peptides share consensus sequences and also a common processing site with two conserved glycine residues in positions -1 and -2. the double-glycine-type leader peptides are unrelated to the n-terminal sig ...	1995	7565085
novel insertion sequence-like element is982 in lactococci.	a novel insertion sequence-like (is) element, designated is982, was found on the lactose plasmid, psk11l, from lactococcus lactis subsp. cremoris sk11 and was located between the origin of replication and the oligopeptide transport gene cluster. the 1003-base pair (bp) is982 was flanked by 18-bp perfect inverted repeats. is982 contained an open reading frame encoding a putative transposase of 296 amino acids. an almost identical is-like element (99% dna sequence identity) was cloned and partiall ...	1995	7568469
the proteolytic pathway of lactococcus lactis.		1995	7570167
virion positions and relationships of lactococcal temperate bacteriophage tp901-1 proteins.	the major proteins of phage tp901-1 virion were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and structural relations were determined using specific antibodies, obtained by affinity purification from a polyclonal serum. a 23-kda protein was identified as the major tail protein, and a 31-kda molecule as the major head protein, respectively. labeling experiments with antibodies against two proteins, with molecular masses of 20 and 19 kda, indicated that they were base ...	1995	7571429
applications of confocal microscopy to fat globule structure in cheese.		1995	7572372
cloning and molecular analysis of the dihydrofolate reductase gene from lactococcus lactis.	the lactococcus lactis gene encoding trimethoprim resistance has been cloned and expressed in escherichia coli and bacillus subtilis. several lines of evidence indicate that the cloned gene encodes dihydrofolate reductase (dhfr). (i) it fully complements the fol "null" mutation in e. coli. (ii) nucleotide sequencing of the cloned fragment revealed the presence of one open reading frame encoding a protein that shares homology with the family of bacterial dhfr enzymes. (iii) overexpression of this ...	1995	7574597
detection and characterization of lactose-utilizing lactococcus spp. in natural ecosystems.	the presence of lactose-utilizing lactococcus species in nondairy environments was studied by using identification methods based on pcr amplification and (sub)species-specific probes derived from 16s rrna sequences. environmental isolates from samples taken on cattle farms and in the waste flow of a cheese production plant were first identified to the genus level, using a lactococcus genus-specific probe. isolates which showed a positive signal with this probe were further identified to the (sub ...	1995	7574616
expression of lactococcin a and pediocin pa-1 in heterologous hosts.	pediocin pa-1 production, immunity and secretion are specified by a cluster of four genes in pediococcus acidilactici pac1.0. the production by, secretion of, and immunity to lactococcin a of lactococcus lactis are also determined by four genes. here, expression of the pediocin operon in lactococcus lactis is reported, which could only be achieved by placing it under control of a lactococcal promoter. expression of the lactococcin a operon in pediococcus is also described: recombinant clones of ...	1995	7576505
16s-23s and 23s-5s intergenic spacer regions of streptococcus thermophilus and streptococcus salivarius, primary and secondary structure.	the 16s-23s intergenic spacer region (spacer region 1) of streptococcus salivarius, s. thermophilus, and lactococcus lactis subsp. cremoris and the 23s-5s intergenic spacer region (spacer region 2) of s. salivarius and l. lactis subsp. cremoris were sequenced and compared with the spacer regions 1 and 2 of other streptococci. a high degree of intraspecific conservation was observed for s. thermophilus and l. lactis, and very similar sequences were found for s. salivarius and s. thermophilus. whe ...	1995	7580797
characterization of diacetin b, a bacteriocin from lactococcus lactis subsp. lactis bv. diacetylactis ul720.	fourteen lactococcus lactis strains showing inhibitory activity against listeria innocua sicc 4202 were isolated from different french raw milks and raw milk cheeses and screened for bacteriocin production by the triple layer method under conditions that eliminate the effects of lactic acid and hydrogen peroxide. three bacteriocinogenic strains (two lactococcus lactis subsp. lactis bv. diacetylactis ul719 and ul720 and one lactococcus lactis subsp. lactis ul730) were selected for their high capa ...	1995	7585360
generation of auxotrophic mutants of enterococcus faecalis.	a 22-kb segment of chromosomal dna from enterococcus faecalis og1rf containing the pyrimidine biosynthesis genes pyrc and pyrd was previously detected as complementing escherichia coli pyrc and pyrd mutations. in the present study, it was found that the e. faecalis pyrimidine biosynthetic genes in this clone (designated pkv48) are part of a larger cluster resembling that seen in bacillus spp. transposon insertions were isolated at a number of sites throughout the cluster and resulted in loss of ...	1995	7592480
the lactococcal lmrp gene encodes a proton motive force-dependent drug transporter.	to genetically dissect the drug extrusion systems of lactococcus lactis, a chromosomal dna library was made in escherichia coli and recombinant strains were selected for resistance to high concentrations of ethidium bromide. recombinant strains were found to be resistant not only to ethidium bromide but also to daunomycin and tetraphenylphosphonium. the drug resistance is conferred by the lmrp gene, which encodes a hydrophobic polypeptide of 408 amino acid residues with 12 putative membrane-span ...	1995	7592810
autoregulation of nisin biosynthesis in lactococcus lactis by signal transduction.	the post-translationally modified, antimicrobial peptide nisin is secreted by strains of lactococcus lactis that contain the chromosomally located nisin biosynthetic gene cluster nisabtciprkfeg. when a 4-base pair deletion is introduced into the structural nisa gene (delta nisa), transcription of delta nisa is abolished. transcription of the delta nisa gene is restored by adding subinhibitory amounts of nisin, nisin mutants, or nisin analogs to the culture medium, but not by the unmodified precu ...	1995	7592991
isolation of lactococcus lactis nonsense suppressors and construction of a food-grade cloning vector.	nonsense suppressor strains of lactococcus lactis were isolated using plasmids containing nonsense mutations or as revertants of a nonsense auxotrophic mutant. the nonsense suppressor gene was cloned from two suppressor strains and the dna sequence determined. one suppressor is an ochre suppressor with an altered trna(gln) and the other an amber suppressor with an altered trna(ser). the nonsense suppressors allowed isolation of nonsense mutants of a lytic bacteriophage and suppressible auxotroph ...	1995	7596286
effects of the generation of single-stranded dna on the maintenance of plasmid pmv158 and derivatives in different bacillus subtilis strains.	the effects of the single-strand origins (ssos) of plasmid pmv158 on (i) the conversion of its single-stranded (ss) replication intermediates to double-stranded (ds) plasmid dna and (ii) its maintenance were analyzed. the rolling-circle plasmid pmv158, which replicates via ssdna intermediates, contains two single-strand origins (ssos) of replication, pala and palu. in this paper the results obtained with bacillus subtilis are described; complementary studies with lactococcus lactis are presented ...	1995	7597110
effects of the generation of single-stranded dna on the maintenance of plasmid pmv158 and derivatives in lactococcus lactis.	the effects of the single-strand origins (ssos) of the broad-host-range streptococcal plasmid pmv158 on (i) the conversion of its single-stranded (ss) dna replication intermediates to double-stranded (ds) plasmid dna and (ii) its maintenance were analyzed. pmv158 is distinguished from most other plasmids that replicate by the rolling-circle mechanism by the presence of two single-strand origins of replication, pala and palu. in this paper the results obtained with lactococcus lactis are presente ...	1995	7597111
sequence analysis of a 5.6 kb fragment of chromosome ii from saccharomyces cerevisiae reveals two new open reading frames next to cdc28.	the sequence of a 5653 bp dna fragment of the right arm of chromosome ii of saccharomyces cerevisiae contains two unknown open reading frames (ybr1212 and ybr1213) next to gene cdc28. gene disruption reveals both putative genes as non-essential. orf ybr1212 encodes a predicted protein with 71% similarity and 65% identity (total polypeptide of 376 aa) with the 378 aa surl protein of s. cerevisiae, while the putative product of orf ybr1213, which is strongly expressed, has 28% identity with a lact ...	1995	7597849
induction of thermotolerance by chemical agents in lactococcus lactis subsp. lactis il1403.	like in other organisms tested to date, adapted cells of lactococcus lactis subsp. lactis il1403 pretreated at 42 degrees c for 30 min develop a thermotolerant state, i.e. an increased ability to survive subsequent exposure to a lethal challenge temperature (52 degrees c for 15 or 30 min). in different cellular systems, chemicals as diverse as divalent metal salts, natural or synthetic compounds trigger the development of thermotolerance. yet, in l. lactis subsp. lactis il1403, among the 17 chem ...	1995	7599033
characterization of the lactococcal abid1 gene coding for phage abortive infection.	lactococcal phage abortive infection (abid1) determined by plasmid pil105 is active on both prolate- and small-isometric-head phages of the c6a and 936 phage groups, respectively, which are considered two different species. the abi phenotype was found to be encoded by a single gene, designated abid1. the abid1-encoded protein (351 amino acids) does not show homology with any known protein and has a deduced isoelectric point of 10. it also possesses two helix-turn-helix structures and an unusuall ...	1995	7601848
phage operon involved in sensitivity to the lactococcus lactis abortive infection mechanism abid1.	phage bil66 is unable to grow on lactococcus lactis cells harboring the abortive infection gene abid1. spontaneous phage mutants able to grow on abid1 cells were used to study phage-abi interaction. a 1.33-kb dna segment of a mutant phage allowed growth of abid1s phages in abid1 cells when present in trans. sequence analysis of this segment revealed an operon composed of four open reading frames, designated orf1 to orf4. the operon is transcribed 10 min after infection from a promoter presenting ...	1995	7601849
restriction-modification systems in lactococcus lactis.	several restriction-modification (r-m) systems have been identified in lactococcus lactis. most of the systems have been plasmid encoded and function as phage-resistance mechanisms. at least five different type-ii r-m systems, llaai, llabi, llaci, lladi and llaei, were identified in isolates from a mixed cheddar starter culture. llaai and llabi recognized the dna sequences 5'- decreases gatc-3' and 5'-c decreases tryag-3', respectively. the genes coding for the llaai and llabi r-m systems have b ...	1995	7607475
the ssoii and nlax dna methyltransferases: overproduction and functional analysis.	overproduction of the nlax dna methyltransferase (m.nlax) in an escherichia coli host conferred resistance to ssoii restriction endonuclease (r.ssoii) digestion. this suggested an overlap of sequence specificity between m.nlax and m.ssoii, the latter of which modifies the internal cytosine of the target sequence 5'-ccngg-3'. a variant of m.nlax (m.sso/nla), containing an n-terminal extension from m.ssoii, was also enzymatically active. using deletion analysis, the n-terminal 71 amino-acid residu ...	1995	7607533
cloning and partial characterization of regulated promoters from lactococcus lactis tn917-lacz integrants with the new promoter probe vector, pak80.	transposon tn917-ltv1 was used to produce a collection of lactococcus lactis strains with fusion of a promoterless lacz gene to chromosomal loci. screening 2,500 tn917-ltv1 integrants revealed 222 that express beta-galactosidase on plates at 30 degrees c. pulsed-field gel electrophoresis revealed tn917-ltv1 insertions in at least 13 loci in 15 strains analyzed. integrants in which beta-galactosidase expression was regulated by temperature or ph and/or arginine concentration were isolated. in mos ...	1995	7618865
genetic marking of lactococcus lactis shows its survival in the human gastrointestinal tract.	a human feeding study was performed with lactococcus lactis tc165.5, which is genetically marked by insertion of the sucrose-nisin conjugative transposon tn5276 and chromosomal resistance to rifampin and streptomycin. the fate of strain tc165.5 and its nucleic acids was monitored by conventional plating methods and by molecular detection techniques based on specific pcr amplification of the nisin (nisa) gene from dna extracted from human feces. a method was developed for the efficient extraction ...	1995	7618890
purification and cloning of dna fragments fractionated on agarose gels.	purification of dna fragments from acrylamide or agarose gels is a commonly used technique in the molecular biology laboratory. this article describes a rapid, efficient, and inexpensive method of purifying dna fractions from an agarose gel. the purified dna is suitable for use in a wide range of applications including ligation using dna ligase. the procedure uses standard high-melting-temperature agarose and normal tbe electrophoresis buffer. in addition, the protocol does not involve the use o ...	1995	7620974
purification and characterization of a small membrane-associated sugar phosphate phosphatase that is allosterically activated by hpr(ser(p)) of the phosphotransferase system in lactococcus lactis.	in the gram-positive bacterium, lactococcus lactis, nonmetabolizable cytoplasmic sugar phosphates, accumulated by the phosphoenolpyruvate:sugar phosphotransferase system, are rapidly dephosphorylated and expelled from the cell upon addition of glucose (inducer expulsion). our recent studies have established that a metabolite-activated, atp-dependent protein kinase that phosphorylates serine-46 in hpr of the phosphoenolpyruvate:sugar phosphotransferase system activates a sugar phosphate phosphata ...	1995	7622485
the codon usage of the nisz operon in lactococcus lactis n8 suggests a non-lactococcal origin of the conjugative nisin-sucrose transposon.	an 11.6 kb area downstream from the structural gene of nisin z in the conjugative nisin-sucrose transposon of lactococcus lactis subsp. lactis n8 was cloned and sequenced. analysis of the sequence revealed eight open reading frames, niszbtclprk, followed by a putative rho-independent terminator (delta g degrees = -4.7 kcal/mol). the c-terminal hydrophilic domain of the nisk protein is homologous to the c-termini of several histidine kinases of bacterial two-component regulator systems, such as s ...	1995	7626780
characterization and heterologous expression of the tetl gene and identification of iso-iss1 elements from enterococcus faecalis plasmid pjh1.	the tetracycline-resistance (tcr) determinant of the enterococcus faecalis plasmid pjh1 has been identified and located on a 2.2-kb rsai-ecori fragment. the fragment was cloned in escherichia coli, and specified tcr in this host. the nucleotide (nt) sequence of the cloned fragment showed the presence of an open reading frame (orf) of 1374 bp, designated tetl. the nt sequence of tetl from pjh1 was identical to that of the tetl present on pls1 from streptococcus agalactiae. upstream of the pjh1 te ...	1995	7628724
homology modelling of the lactococcus lactis leader peptidase nisp and its interaction with the precursor of the lantibiotic nisin.	a model is presented for the 3-d structure of the catalytic domain of the putative leader peptidase nisp of lactococcus lactis, and the interaction with its specific substrate, the precursor of the lantibiotic nisin. this homology model is based on the crystal structures of subtilisin bpn' and thermitase in complex with the inhibitor eglin. predictions are made of the general protein fold, inserted loops, ca2+ binding sites, aromatic interactions and electrostatic interactions of nisp. cleavage ...	1995	7630881
specificity of peptide transport systems in lactococcus lactis: evidence for a third system which transports hydrophobic di- and tripeptides.	a proton motive force-driven di-tripeptide carrier protein (dtpt) and an atp-dependent oligopeptide transport system (opp) have been described for lactococcus lactis mg1363. using genetically well-defined mutants in which dtpt and/or opp were inactivated, we have now established the presence of a third peptide transport system (dtpp) in l. lactis. the specificity of dtpp partially overlaps that of dtpt. dtpp transports preferentially di- and tripeptides that are composed of hydrophobic (branched ...	1995	7642491
cloning and characterization of the abortive infection genetic determinant abid isolated from pbf61 of lactococcus lactis subsp. lactis kr5.	a 6.3-kb fragment from pbf61 in lactococcus lactis subsp. lactis kr5 was cloned and found to confer an abortive phage infection (abi+) phenotype exhibiting a reduction in efficiency of plating and plaque size for small isometric- and prolate-headed bacteriophages sk1 and c2, respectively, and to produce a 10-fold decrease in c2 phage burst size. phage adsorption was not significantly reduced. an open reading frame of 1,098 bp was sequenced and designated abid. tn5 mutagenesis confirmed that abid ...	1995	7646042