| [isolation of rec mutants of bacillus subtilis via insertional mutagenesis]. | a number of mutants supersensitive to mytomycine c were isolated via insertion of tn917 into bacillus subtilis chromosome. six rec mutants with lower transformation frequency, though with nondisturbed capacity of dna binding and uptake, were isolated. two of these mutations are situated in those chromosomal sites where location of rec genes had not yet been registered. | 1991 | 1651879 |
| [nucleotide sequences cleavable by bacillus subtilis dna gyrase in vivo]. | | 1991 | 1653129 |
| cloning and characterization of a rhizobium meliloti homolog of the escherichia coli cell division gene ftsz. | the ftsz gene is essential for initiation of cell division in escherichia coli and bacillus subtilis. to begin our studies of division arrest during differentiation of rhizobium meliloti bacteroids, we isolated a r. meliloti ftsz homolog, ftszrm. degenerate primers directed towards a conserved region of ftsz were used to amplify a segment of r. meliloti dna by polymerase chain reaction, and the product of this reaction was then used to isolate positive clones from a bacteriophage library. the dn ... | 1991 | 1653222 |
| reactivity of the bacillus subtilis succinate dehydrogenase complex with quinones. | the succinate dehydrogenase isolated from bacillus subtilis was found to catalyze the oxidation of succinate with hydrophilic quinones. either naphthoquinones or benzoquinones served as acceptors. the enzyme activity increased with the redox potential of the quinone. the highest turnover number was commensurate with that of the bacterial succinate respiration in vivo. the succinate dehydrogenase was similarly active in fumarate reduction with quinols. the highest activity was obtained with the m ... | 1991 | 1655027 |
| a dna curvature can substitute phage phi 29 regulatory protein p4 when acting as a transcriptional repressor. | binding of phage phi 29 regulatory protein p4 to its target sequences produces a strong bend in the dna that is important for activation of the late a3 promoter (pa3). protein p4 binding site in pa3 overlaps with the divergently transcribed main early promoter. pa2b, which suggested that p4 could also act as a repressor. we show that protein p4 both excludes bacillus subtilis sigma a-rna polymerase from pa2b and directs it to the divergently transcribed a3 promoter. although steric hindrance is ... | 1991 | 1655421 |
| detection and characterization of naturally occurring plasmids in bacillus licheniformis. | twenty-two bacillus licheniformis strains, freshly isolated from pasture-land, were studied for the presence of plasmid dna. among these strains, 14 were shown to harbor one or more plasmids of different size. southern-hybridization experiments showed a high homology between all plasmids investigated and a 2.2-kb pvuii/hindiii fragment of pbl1, a b. licheniformis plasmid previously isolated. three fragments of pbl1, including the 2.2-kb pvuii/hindiii region, were cloned into pjh101 vector. the r ... | 1991 | 1655561 |
| catabolite repression vs derepression, an approach to differentiation during sporulation in bacillus subtilis. | glutamine, like glucose, repressed sporulation and the synthesis of mycobacillin and dipicolinic acid by bacillus subtilis, and these syntheses were depressed by dibutyryl cyclic gmp but not by dibutyryl cyclic amp. neither of these dibutyryl cyclic nucleotides affected sporulation or a number of spore-associated parameters in the strain under normal physiological conditions. mutants insensitive to glutamine repression were indifferent to the addition of either of the dibutyryl cyclic nucleotide ... | 1991 | 1655689 |
| an improved method for the small scale preparation of bacteriophage dna based on phage precipitation by zinc chloride. | | 1991 | 1656393 |
| mechanisms of clinical resistance to fluoroquinolones in enterococcus faecalis. | about 10% of 100 clinical isolates of enterococcus faecalis were resistant to greater than or equal to 25 micrograms of norfloxacin, ofloxacin, ciprofloxacin, and temafloxacin per ml. in this study, the dna gyrase of e. faecalis was purified from a fluoroquinolone-susceptible strain (atcc 19433) and two resistant isolates, ms16968 and ms16996. strains ms16968 and ms16996 were 64- to 128-fold and 16- to 32-fold less susceptible, respectively, to fluoroquinolones than was atcc 19433; mics of nonqu ... | 1991 | 1656852 |
| identification of dinr, a dna damage-inducible regulator gene of bacillus subtilis. | a bacillus subtilis strain deficient in homologous recombination was isolated from a library of tn917lac insertion mutants. the interrupted locus consists of an open reading frame encoding a 22,823-dalton polypeptide. analysis of the deduced amino acid sequence revealed 34% identity and 47.3% similarity with the lexa protein from escherichia coli. the gene was designated dinr. it is located between the reca and thya genetic markers, at 162 degrees on the b. subtilis chromosome. the dinr gene was ... | 1991 | 1657879 |
| in vitro stimulation of immune functions by lipids derived from macrophages exposed to bacterial peptidoglycan. | it has previously been established that the processing of bacillus subtilis cell walls by the macrophage-like cell line raw264 leads to the formation of peptidoglycolipids containing glycopeptides of bacterial origin. in view of the immunologic activities associated with lipophilic muramyl peptide derivatives, lipid extracts derived from macrophages exposed to bacterial cell walls were assayed for mitogenicity. the crude lipid extract derived from raw264 cells exposed to bacterial cell walls gav ... | 1991 | 1658148 |
| dna-bending properties of tf1. | transcription factor 1 (tf1) is the bacillus subtilis phage spo1-encoded member of the family of dna-binding proteins that includes escherichia coli hu and integration host factor, ihf. a gel electrophoretic retardation method has been used to show that a tf1 dimer binding to one of its preferred sites in (5-hydroxymethyl)uracil (hmura)-containing dna sharply bends the latter. in fact, the dna-bending properties of tf1 and e. coli ihf are indistinguishable. substitutions at amino acid 61 in the ... | 1991 | 1658334 |
| analysis of the gluconate (gnt) operon of bacillus subtilis. | the gluconate (gnt) operon of bacillus subtilis includes the gntr, gntk, gntp, and gntz genes, respectively encoding the transcriptional repressor of the operon, gluconate kinase, the gluconate permease, and an unidentified open reading frame (fujita and fujita, 1987). we have compared the proteins encoded by the gnt operon of b.subtilis with published sequences and showed that (i) the gluconate repressor is homologous to several putative regulatory proteins in escherichia coli, (ii) the glucona ... | 1991 | 1659648 |
| mutants of bacillus species isolated on the basis of protonophore resistance are deficient in fatty acid desaturase activity. | the fatty acid desaturase activity in cell extracts of bacillus subtilis was characterized and found to be o2 dependent, nadh dependent, and cyanide sensitive. in cell fractionation studies, only 10% of the desaturase activity was recovered in the membrane fraction; the addition of cytosolic factors, which by themselves were devoid of activity, restored membrane activity to the level found in the unfractionated cell extracts. nadh was preferred over nadph as an electron donor, and palmitoyl-coen ... | 1991 | 1660453 |
| molecular cloning and sequencing of a gene from alkaliphilic bacillus firmus of4 that functionally complements an escherichia coli strain carrying a deletion in the nhaa na+/h+ antiporter gene. | a gene has been cloned from a dna library from alkaliphilic bacillus firmus of4 that functionally complements a mutant strain of escherichia coli, nm81, that carries a deletion for one of that strain's na+/h+ antiporter genes (delta nhaa). the cloned alkaliphile gene restored to nm81 the ability to grow at ph 7.5 in the presence of 0.6 m nacl and on 100 mm li+ in the presence of melibiose, and concomitantly led to an increase in the membrane associated na+/h+ antiport activity. the biologically ... | 1991 | 1660475 |
| methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. | there is a need to standardize the ndf procedure. procedures have varied because of the use of different amylases in attempts to remove starch interference. the original bacillus subtilis enzyme type iiia (xia) no longer is available and has been replaced by a less effective enzyme. for fiber work, a new enzyme has received aoac approval and is rapidly displacing other amylases in analytical work. this enzyme is available from sigma (number a3306; sigma chemical co., st. louis, mo). the original ... | 1991 | 1660498 |
| effectiveness of dental office instrument sterilization procedures. | to evaluate instrument sterilization procedures in minnesota, biological indicators were used to monitor 406 sterilizers in 381 dental offices. findings suggest a general improvement in instrument performance over that of a decade ago, but sterilization failure rates are still too high. sterilizer operator errors are a major cause of sterilization failures. bis are useful in monitoring sterilization performance only when sterilization procedures are performed consistently and competently by well ... | 1991 | 1660501 |
| organization and characterization of three genes involved in d-xylose catabolism in lactobacillus pentosus. | a cluster of three genes involved in d-xylose catabolism (viz. xylose genes) in lactobacillus pentosus has been cloned in escherichia coli and characterized by nucleotide sequence analysis. the deduced gene products show considerable sequence similarity to a repressor protein involved in the regulation of expression of xylose genes in bacillus subtilis (58%), to e. coli and b. subtilis d-xylose isomerase (68% and 77%, respectively), and to e. coli d-xylulose kinase (58%). the cloned genes repres ... | 1991 | 1660563 |
| characterization of a region of the enterococcus faecalis plasmid pam beta 1 which enhances the segregational stability of pam beta 1-derived cloning vectors in bacillus subtilis. | the nucleotide sequence of a 2.13-kb ecori-hindiii, pam beta 1-derived fragment, isolated from the gram-positive cloning vector phv1431, has been determined and shown to encode two orfs. orf h encodes for a protein of 23,930 da which exhibits substantial homology to bacterial site-specific recombinases, particularly the resolvases of the gram-positive transposons tn917 (30.3% identity) and tn552 (31.6% identity) and the clostridial plasmid pip404 (27.1% identity). the second orf (i) is incomplet ... | 1991 | 1661428 |
| introduction of tn916 and pam beta 1 into streptococcus bovis jb1 by conjugation. | the transposon tn916 and self-mobilizing plasmid pam beta 1 were conjugated from enterococcus faecalis to the ruminal bacterium streptococcus bovis jb1. transconjugants were identified by resistance to tetracycline (tn916) or erythromycin (pam beta 1) and by southern hybridization analyses. transfer frequencies were 7.0 x 10(-6) and 1.0 x 10(-6) per recipient cell for tn916 and pam beta 1, respectively. the transconjugants jb1/tn916 and jb1/pam beta 1 were used as donors for matings with e. faec ... | 1991 | 1662940 |
| sequence specificity of bacillus subtilis dna gyrase in vivo. | linearization of pbg0 (a hydrid between escherichia coli plasmid pbr322 and staphylococcus aureus plasmid pub110) was performed by lysis of the oxolinic acid treated bacillus subtilis protoplasts with sodium dodecyl sulfate. this plasmid dna linearization was used both for a detailed mapping of dna gyrase cleavage sites of various strength and for the nucleotide sequence determinations at the points of gyrase-mediated scissions by introducing the xhoi linker dna. a total of 40 plasmids carrying ... | 1991 | 1663896 |
| [the role of dna-gyrase from bacillus subtilis during intermolecular irregular recombination]. | the location of oxolinis acid-induced gyrase cleavage sites on pbr322 and pub110 plasmid dna in bacillus subtilis cells has been studied and established. the treated bacillus subtilis protoplasts were used in the study. coordinates of the gyrase cleavage sites were compared to the location of the illegitimate recombination sites precisely mapped on the plasmid genomes. the obtained data indicate involvement of the dna gyrase in formation of a fraction of recombinants in bacillus subtilis. | 1991 | 1664491 |
| control of the initiation of sporulation in bacillus subtilis by a phosphorelay. | sporulation in bacillus subtilis is a developmental process induced as a response to nutritional stress. activation of sporulation-specific gene transcription is under the control of the spooa gene product. the spooa protein and the spoof protein are both homologous to response regulator proteins of two-component regulatory systems which control bacterial responses to a variety of environmental challenges. response regulators are activated by specific kinases which phosphorylate them. in this st ... | 1991 | 1664534 |
| a genetic analysis of spo0a structure and function. | mutations that enhanced sporulation in the presence of high concentrations of key nutrients (coi mutations) included at least four lesions within the phosphoacceptor domain of spo0a, a member of the response regulator family of "two-component" signal transduction proteins. the nature of these mutations and the phenotypes they produce support the model that the sporulation state of spo0a controls the initiation of sporulation. this was further supported by the observation that site-directed mutat ... | 1991 | 1664535 |
| the role of negative control in sporulation. | negative controls play an important role in the regulation of differentiation in many organisms. sporulation in bacillus subtilis is also regulated by dna-binding proteins which exert a repressive effect on genes which are essential for this process. abrb represses spo0h, coding for sigma h. one of the earliest events in the initiation of sporulation is the lifting of this repression so that more sigma h can be made. as part of an rna polymerase holoenzyme, this positive transcription factor is ... | 1991 | 1664536 |
| plasmid instability and molecular cloning in bacillus subtilis. | | 1991 | 1664537 |
| a host factor absent from lactococcus lactis subspecies lactis mg1363 is required for conjugative transposition. | in matings between lactococcus lactis strains, the conjugative transposons tn916 and tn919 are found in the chromosome of the transconjugants in the same place as in the chromosome of the donor, indicating that no transposition has occurred. in agreement with this, the frequency of l. lactis transconjugants from intraspecies matings is the same whether the donor contains the wild-type form of the transposon or the mutant tn916-int1, which has an insertion in the transposon's integrase gene. howe ... | 1991 | 1667220 |
| a pharmacokinetic study of e-4441, a new quinolone, in the rat, mouse and cynomolgus monkey. | the purpose of this present work has been to study the pharmacokinetical profile of e-4441 in the rat, mouse and cynomolgus monkey. analytical determination of the levels in plasma, urine and organs was affected by two different techniques: a microbiological agar diffusion assay with bacillus subtilis, and hplc with preliminary extraction in chloroform (ph 8.5). the kinetic behaviour of the unchanged substance was similar in the three animal species studied. absorption and excretion took place r ... | 1991 | 1668199 |
| identification of genes and gene products whose expression is activated during nitrogen-limited growth in bacillus subtilis. | the levels of urease and asparaginase were elevated 25- and 20-fold, respectively, in extracts of bacillus subtilis cells grown in medium containing nitrogen sources that are poor sources of ammonium (nh4+) compared with the levels seen in extracts of cells grown in medium containing nitrogen sources that are good sources of nh4+. to determine whether a collection of genes whose expression responds to nitrogen availability could be isolated, a library of tn917-lacz insertions was screened for ni ... | 1991 | 1670935 |
| intracellular location of the autolytic n-acetylmuramyl-l-alanine amidase in bacillus subtilis 168 and in an autolysis-deficient mutant by immunoelectron microscopy. | antisera against purified autolytic n-acetylmuramyl-l-alanine amidase from bacillus subtilis 168 were prepared in rabbits. they neutralized the enzymatic action of the purified amidase acting on isolated sodium dodecyl sulfate (sds)-treated walls from the same organism. they also inhibited the lysis of native walls, but only after the walls lysed partially. amidase adsorbed to insoluble walls still combined with antibody. antisera did not stop the lysis of whole cells. lowicryl hm20 sections of ... | 1991 | 1671387 |
| the bacillus subtilis hemaxcdbl gene cluster, which encodes enzymes of the biosynthetic pathway from glutamate to uroporphyrinogen iii. | we have recently reported (m. petricek, l. rutberg, i. schröder, and l. hederstedt, j. bacteriol. 172: 2250-2258, 1990) the cloning and sequence of a bacillus subtilis chromosomal dna fragment containing hema proposed to encode the nad(p)h-dependent glutamyl-trna reductase of the c5 pathway for 5-aminolevulinic acid (ala) synthesis, hemx encoding a hydrophobic protein of unknown function, and hemc encoding hydroxymethylbilane synthase. in the present communication, we report the sequences and id ... | 1991 | 1672867 |
| molecular cloning and sequence analysis of the x-prolyl dipeptidyl aminopeptidase gene from lactococcus lactis subsp. cremoris. | lactococcus lactis subsp. cremoris p8-2-47 contains an x-prolyl dipeptidyl aminopeptidase (x-pdap; ec 3.4.14.5). a mixed-oligonucleotide probe prepared on the basis of the n-terminal amino acid sequence of the purified protein was made and used to screen a partial chromosomal dna bank in escherichia coli. a partial xbai fragment cloned in puc18 specified x-pdap activity in e. coli clones. the fragment was also able to confer x-pdap activity on bacillus subtilis. the fact that none of these organ ... | 1991 | 1674655 |
| efflux-mediated multidrug resistance in bacillus subtilis: similarities and dissimilarities with the mammalian system. | bacillus subtilis cells selected for their resistance to rhodamine 6g demonstrated a multidrug-resistance (mdr) phenotype resembling that of mammalian mdr cells. like mdr in mammalian cells, mdr in bacteria was mediated by the efflux of the drugs from the cells. the bacterial multidrug efflux system transported similar drugs and was sensitive to similar inhibitors as the mammalian multidrug transporter, p-glycoprotein. the gene coding for the bacterial multidrug transporter, like the p-glycoprot ... | 1991 | 1675788 |
| characterisation of a pseudomonas aeruginosa twitching motility gene and evidence for a specialised protein export system widespread in eubacteria. | type-4 fimbriae (pili) are associated with a phenomenon known as twitching motility, which appears to be involved with bacterial translocation across solid surfaces. pseudomonas aeruginosa mutants which produce fimbriae, but which have lost the twitching motility function, display altered colony morphology and resistance to fimbrial-specific bacteriophage. we have used phenotypic complementation of such mutants to isolate a region of dna involved in twitching motility. this region was physically ... | 1991 | 1676385 |
| identification of dna sequences involved in regulating bacillus subtilis glnra expression by the nitrogen source. | the dna binding protein, glnr, encoded by glnr, is believed to be directly responsible for regulating glnra expression in bacillus subtilis. identification of cis-acting loci involved in glnra control is the focus of this study. analysis of glnra-lacz transcriptional fusions harboring deletions extending into the promoter region demonstrated that sequences upstream from position -35, relative to the transcription start-point, were necessary for nitrogen source regulation. these sequences include ... | 1991 | 1677426 |
| purification and characterization of a repressor for the bacillus cereus glnra operon. | we report the overexpression, purification, and properties of the regulatory protein, glnr, for glutamine synthetase synthesis of bacillus cereus. the protein was found to be a dimer with a molecular weight of approximately 30,000, and its subunit molecular weight was 15,000 in agreement with that (15,025) of deduced amino acid sequence of glnr. the purified glnr protein bound specifically to the promoter region of the glnra operon of b. cereus and bacillus subtilis. the binding of the glnr prot ... | 1991 | 1677938 |
| purification and amino acid sequence of a bitter gourd inhibitor against an acidic amino acid-specific endopeptidase of streptomyces griseus. | an inhibitor (bgia) against an acidic amino acid-specific endopeptidase of streptomyces griseus (glu s. griseus protease) was isolated from seeds of the bitter gourd momordica charantia l., and its amino acid sequence was determined. the molecular weight of bgia based on the amino acid sequence was calculated to be 7419. bgia competitively inhibited glu s. griseus protease with an inhibition constant (ki) of 70 nm, and gel filtration analyses suggested that bgia forms a 1:1 complex with this pro ... | 1991 | 1679433 |
| possible intermediate steps in the evolution of a prokaryotic developmental system. | sigma factors (sigma) are transcription factors that operate global switches in gene expression in prokaryotes. they work by directing core rna polymerase to specific cis-acting promoter sequences; each sigma has a cognate class of promoters with specific sequence characteristics. in bacillus subtilis four different sigma factors have been implicated in the regulation of gene expression during spore formation, which is a simple differentiation system involving two cell types. in this review i sh ... | 1991 | 1679545 |
| molecular cloning and sequencing of a major bacillus subtilis autolysin gene. | a major bacillus subtilis 168s autolysin (n-acetylmuramoyl-l-alanine amidase [ec 3.5.1.28]) was purified and then cleaved with cyanogen bromide. the n-terminal amino acid sequence of one of the resultant peptides was determined in order to make synthetic oligonucleotides. a 2.5-kb ecori fragment was cloned into escherichia coli jm109 and detected by colony hybridization by using the oligonucleotides as probes. sequencing of the insert showed the presence of an open reading frame (designated cwlb ... | 1991 | 1682302 |
| cloning, expression, sequence analysis and biochemical characterization of an autolytic amidase of bacillus subtilis 168 trpc2. | by use of a functional assay for activity, an autolysin structural gene was cloned on a 3 kb ecori dna fragment from a lambda gt11 expression library of bacillus subtilis 168 trpc2 genomic dna. sequencing of the fragment showed five open reading frames, the central one of which encoded the lytic enzyme as found by subclone activity mapping and its homology to a recently sequenced autolysin gene. the protein had a deduced sequence of 272 amino acids and a molecular mass of 29957 da. when expresse ... | 1991 | 1683402 |
| bacillus subtilis cytochrome oxidase mutants: biochemical analysis and genetic evidence for two aa3-type oxidases. | the ctabcdef genes coding for cytochrome c oxidase were found to reside adjacent to a regulatory gene ctaa at 127 degrees on the bacillus subtilis chromosome. the structural genes for subunits i and ii, ctad and ctac, were deleted by gene-replacement using a phleomycin-resistance marker. the mutant was unable to oxidize n,n,n',n'-tetramethyl-p-phenylene-diamine and oxidized cytochrome c at a significantly lower rate. absorption spectra of the mutant and wild-type membranes confirmed the presence ... | 1991 | 1685007 |
| characterization of bacillus subtilis glutamine synthetase by limited proteolysis. | the inactivation of native glutamine synthetase (gs) from bacillus subtilis by trypsin, chymotrypsin, or subtilisin followed pseudo-fast order kinetics. trypsin cleaved the polypeptide chain of gs into two principal fragments, one of about 43,000 (mr) and the other of smaller than 10,000. chymotrypsin and subtilisin caused similar cleavage of gs. a large fragment (mr 35,000) and one smaller than 10,000 were detected on sds-page. the nicked protein remained dodecameric, as observed on gel filtrat ... | 1991 | 1685734 |
| identification of amino acid residues modified by two atp analogs in bacillus subtilis glutamine synthetase. | bacillus subtilis glutamine synthetase was modified by two atp analogs, 5'-p-fluorosulfonylbenzoyladenosine (fsba) and 8-azidoadenosine 5'-triphosphate (8-n3-atp), each one containing either mg2+ or mn2+. the fsba labeled peptide was monitored by measuring the characteristic absorbance of the 4-carboxybenzenesulfonyl (cbs) part at 243 nm. the 8-n3atp photolabeled peptide could also be monitored by measuring its absorption at 310 nm. a single cbs-labeled tryptic peptide was obtained, spanning res ... | 1991 | 1686028 |
| the killing activity of microwaves on some non-sporogenic and sporogenic medically important bacterial strains. | the killing activity of microwaves of 2450 mhz frequency and 325 w, 650 w and 1400 w power on some bacterial strains was investigated. vegetative strains of staphylococcus aureus, streptococcus pyogenes group a, escherichia coli, pseudomonas aeruginosa and enterococcus faecalis and spores of bacillus subtilis and bacillis stearothermophilus in aqueous suspensions were exposed to 325 w and 650 w waves for different lengths of time. enterococcus faecalis and spores of b. subtilis and b. stearother ... | 1991 | 1686036 |
| allelic exchange in escherichia coli using the bacillus subtilis sacb gene and a temperature-sensitive psc101 replicon. | to facilitate efficient allelic exchange of genetic information into a wild-type strain background, we improved upon and merged approaches using a temperature-sensitive plasmid and a counter-selectable marker in the chromosome. we first constructed intermediate strains of escherichia coli k12 in which we replaced wild-type chromosomal sequences, at either the fimb-a or lacz-a loci, with a newly constituted dna cassette. the cassette consists of the sacb gene from bacillus subtilis and the neomyc ... | 1991 | 1686293 |
| n-acetylmuramoyl-l-alanine amidase assay based on specific radioactive labeling of muropeptide l-alanine: quantitation of the enzyme activity in the autolysin deficient bacillus subtilis 168, flad strain. | a sensitive and highly reproducible assay for n-acetylmuramoyl-l-alanine amidase (ec 3.5.1.28) was devised, based on specific and homogeneous l-[14c]alanine labeling of the substrate, the peptidoglycan. the method involves partial purification of both the enzyme and the substrate and monitoring the muropeptide cleavage by coupling fluorodinitrobenzene to freed l-alanine nh2 groups. after acid hydrolysis of the substrate, the resulting dnp-l-alanine and l-alanine are separated by tlc, and radioac ... | 1991 | 1686374 |
| electron microscopy study of groel chaperonin: different views of the aggregate appear as a function of cell growth temperature. | we have studied two members of the family of morphogenetic factors or chaperonins, the groel-like factors from escherichia coli and bacillus subtilis, in order to determine the possible structural basis of their related function in promoting the correct and efficient assembly of biological oligomers. the main objective of this work has been to study by transmission electron microscopy the possible changes that these factors may undergo when subjected to a number of different conditions such as c ... | 1991 | 1687110 |
| signal transduction pathway controlling synthesis of a class of degradative enzymes in bacillus subtilis: expression of the regulatory genes and analysis of mutations in degs and degu. | the rates of synthesis of a class of both secreted and intracellular degradative enzymes in bacillus subtilis are controlled by a signal transduction pathway defined by at least four regulatory genes: degs, degu, degq (formerly sacq), and degr (formerly prtr). the degs-degu proteins show amino acid similarities with two-component procaryotic modulator-effector pairs such as ntrb-ntrc, chea-chey, and envz-ompr. by analogy with these systems, it is possible that degs is a protein kinase which coul ... | 1990 | 1688843 |
| escherichia coli 4.5s rna gene function can be complemented by heterologous bacterial rna genes. | the essential 4.5s rna gene of escherichia coli can be complemented by 4.5s rna-like genes from three other eubacteria, including both gram-positive and gram-negative organisms. two of the genes encode rnas similar in size to the e. coli species; the third, from bacillus subtilis, specifies an rna more than twice as large. the heterologous genes are expressed efficiently in e. coli, and the product rnas resemble those produced by cognate cells. we conclude that the heterologous rnas can replace ... | 1990 | 1689715 |
| cascade regulation of spore coat gene expression in bacillus subtilis. | endospores of the gram-positive bacterium bacillus subtilis are encased in a tough protein shell known as the coat. the coat is composed of a dozen or more different structural proteins. we report the identification of and studies on the regulation of promoters governing the expression of coat protein (cot) genes designated b to e encoding polypeptides of 59, 12, 11 and 24 kda, respectively. we show that transcription of genes b, c and d is governed by single promoters and that transcription of ... | 1990 | 1691789 |
| stretch-activated composite ion channels in bacillus subtilis. | the presence of ion-conducting pores in the membrane of bacillus subtilis giant protoplasts was discovered using the patch-clamp technique. membrane stretch caused the activation of several conductances with values in the ns range. the observations indicate the presence of substate levels and of aggregates of channels behaving in a cooperative manner. following repeated stretch cycles, the channels exhibited spontaneous activity. the characteristics of the electrical phenomena afterwards changed ... | 1990 | 1692209 |
| transcriptional regulation of comc: evidence for a competence-specific transcription factor in bacillus subtilis. | comc specifies a protein product that is required for genetic competence in bacillus subtilis. the probable transcriptional start site of comc has been localized by high-resolution primer extension analysis and shown to be preceded by an appropriately positioned sequence that resembles the consensus promoter for the sigma a form of rna polymerase. low-resolution s1 nuclease transcription mapping was used to identify the comc terminator, which is located near a palindromic element recognizable in ... | 1990 | 1694528 |
| high-performance liquid chromatography of transfer ribonucleic acids on spherical hydroxyapatite beads. | high-performance liquid chromatography (hplc) on newly developed spherical beads of hydroxyapatite was applied to the analysis of purified e. coli trnas (val, met, tyr and phe). trnas were eluted from the column separately with appreciable differences in retention time by a 45-min gradient of phosphate buffer (ph 6.8) of concentration from 64 to 123 mm; both the retention times and peak areas of respective trnas were highly reproducible. total trna (trna(total)) preparations obtained from e. col ... | 1990 | 1695908 |
| similar cage-shaped structures for the rna components of all ribonuclease p and ribonuclease mrp enzymes. | | 1990 | 1696176 |
| characterization of chromosomal dna amplifications with associated tetracycline resistance in bacillus subtilis. | endogenous chromosomal dna amplifications with associated tetracycline resistance (tcr) in bacillus subtilis were first described by c. r. wilson and a. e. morgan (j. bacteriol. 163:445-453, 1985). we have confirmed and extended their results, and we show that fusion of protoplasts from tcs b. subtilis 168 trpc2 with polyethylene glycol and regeneration on medium containing 20 micrograms of tetracycline per ml induces tcr regenerants that contain amplified dna. this phenomenon appeared to be rec ... | 1990 | 1697573 |
| secretory s complex of bacillus subtilis: sequence analysis and identity to pyruvate dehydrogenase. | we have cloned the operon coding for the bacillus subtilis s complex, which has been proposed to be a component in protein secretion machinery. a lambda gt10 library of b. subtilis was screened with antiserum directed against the staphylococcus aureus membrane-bound ribosome protein complex, which is homologous to the b. subtilis s complex. two positive overlapping lambda clones were sequenced. the s-complex operon, 5 kilobases in size, was shown to contain four open reading frames and three put ... | 1990 | 1697575 |
| phylogenetic and biochemical evidence for a secondary structure model of a small cytoplasmic rna from bacilli. | small cytoplasmic rna (scrna; 271 nucleotides) is an abundant, stable rna identified in the gram-positive eubacterium bacillus subtilis. several findings suggest an important role of scrna in protein biosynthesis: it shares structural and biochemical features with the escherichia coli 4.5s rna (114 nucleotides), a molecule known to be involved in this process, and it can complement the essential function of 4.5s rna in vivo. the common apical hairpin motif of scrna and 4.5s rna also exists in eu ... | 1990 | 1698156 |
| composite affinity sorbents and their cleaning in place. | making large-scale affinity sorbents that are reusable under acceptable hygienic conditions implies specific treatments for cleaning in place with known aqueous solutions of chemical agents. however, common agents such as sodium hydroxide are frequently considered too drastic for the stability of macromolecular biologically active immobilized ligands. according to a large series of trials, it was found that only a mixture of sodium hydroxide and ethanol was actually effective in sterilizing a so ... | 1990 | 1698196 |
| the organization and evolution of transfer rna genes in mycoplasma capricolum. | the genes for presumably all the trna species in mycoplasma capricolum, a derivative of gram-positive eubacteria, have been cloned and sequenced. there are 30 genes encoding 29 trna species. this number is the smallest in all the known genetic systems except for mitochondria. the sequences of 9 trna genes of them have been previously reported (1-3). twenty-two genes are organized in 5 clusters consisting of nine, five, four and two genes (2 sets), respectively. the other eight genes exist as a s ... | 1990 | 1698277 |
| characterization of a 17 kda protein gene upstream from the small cytoplasmic rna gene of bacillus subtilis. | the bacillus subtilis small cytoplasmic rna (scrna) is the structural homologue of both the rna component of the eukaryotic signal recognition particle (srp) and the escherichia coli 4.5s rna, and it can complement the essential function of the latter rna in vivo. in the course of characterization of the single-copy scrna gene locus (scr) we identified an open reading frame, termed orf17, upstream from scr that encodes an acidic 17 kda protein of unknown function. this analysis involved dna sequ ... | 1990 | 1698458 |
| localization of a second sigh promoter in the bacillus subtilis siga operon and regulation of dnae expression by the promoter. | the presence of a second sigh promoter in the siga operon of bacillus subtilis was demonstrated by use of a promoter probe plasmid, a sigh deletion mutant, primer extension studies, and in vitro transcription with e sigma h holoenzyme. both sigh promoters were expressed at low levels even during the growth phase but were expressed at higher levels during the early stationary phase. expression from the upstream sigh promoter allowed the expression of both dnae and siga genes; however, expression ... | 1990 | 1698762 |
| characterization of a multienzyme complex derived from a bacillus subtilis dna-membrane extract that synthesizes rna and dna precursors. | the activity of a variety of enzymes involved in the synthesis of rna and dna precursors was found to copurify with initiation of dna replication activity. these enzymes included ribo- and deoxyribonucleoside kinases, kinases for their phosphorylated intermediates, and ribonucleoside diphosphate reductase. this precursor-synthesizing complex is part of a bacillus subtilis dna-membrane extract originally shown to contain all of the enzymes and template necessary for initiation of dna replication ... | 1990 | 1698763 |
| temperature-inducible gene expression in bacillus subtilis mediated by the ci857-encoded repressor of bacteriophage lambda. | an efficient system to control the expression of cloned genes in bacillus subtilis was established by introducing the escherichia coli bacteriophage lambda ci857 repressor-pr promoter system into this host. a staphylokinase reporter gene (sak42d), which was fused to the lambda pr promoter was constitutively expressed in b. subtilis even when the ci857 gene was present on the same plasmid. s1 nuclease mapping of the transcription start point confirmed that the pr promoter was active in b. subtili ... | 1990 | 1699846 |
| complementation of an rnase p rna (rnpb) gene deletion in escherichia coli by homologous genes from distantly related eubacteria. | we report the construction of a strain of escherichia coli in which the only functional gene for the rna moiety of rnase p (rnpb) resides on a plasmid that is temperature sensitive for replication. the chromosomal rnase p rna gene was replaced with a chloramphenicol acetyltransferase gene. the conditionally lethal phenotype of this strain was suppressed by plasmids that carry rnase p rna genes from some distantly related eubacteria, including alcaligenes eutrophus, bacillus subtilis, and chromat ... | 1990 | 1699929 |
| cloning and analysis of the bacillus subtilis rpsd gene, encoding ribosomal protein s4. | the rpsd gene, encoding ribosomal protein s4, was isolated from bacillus subtilis by hybridization with oligonucleotide probes derived from the s4 amino-terminal protein sequence. sequence analysis of the cloned dna indicated that rpsd is likely to be monocistronic, in contrast to escherichia coli rpsd, which is located in the alpha operon and is the translational regulator for alpha operon ribosomal protein gene expression in e. coli. the cloned gene was shown to map at position 263 degrees on ... | 1990 | 1699930 |
| rna dependence of the bacteriophage phi 29 dna packaging atpase. | the activity of the dna packaging adenosine triphosphatase (atpase) of the bacillus subtilis bacteriophage phi 29 is dependent upon prohead rna. the 174 nucleotide viral-encoded rna is positioned on the head-tail connector at the portal vertex of the phi 29 precursor shell (prohead). here, the rna interacts with the atp-binding gene 16 product (gp16) to constitute the dna-packaging atpase and initiate dna packaging in vitro. both the prohead connector (gene 10 product, gp10) and gp16 may utilize ... | 1990 | 1700132 |
| changes in the stability of specific mrna species in response to growth stage in bacillus subtilis. | in this study we compared the cellular concentrations and stability of the mrna transcribed from the apre (subtilisin) gene (a gene preferentially expressed in stationary growth phase) with those of a vegetative mrna, succinate dehydrogenase (sdh) mrna. the subtilisin transcript was shown to be at least 3 times more stable in early stationary phase than it is 2 hr further into stationary phase. when cells were shifted from maximum expression of the subtilisin transcript in stationary phase to ph ... | 1990 | 1700430 |
| mapping the active site of ribonuclease p rna using a substrate containing a photoaffinity agent. | ribonuclease p rna is the catalytic moiety of the ribonucleoprotein enzyme that removes precursor sequences from 5'-ends of pre-trnas. a photoaffinity cross-linking agent was coupled to the substrate phosphate on which rnase p acts and used to map nucleotides in the vicinity of the catalytic site of this ribozyme. mature trna(phe) containing a 5'-thiophosphate was synthesized by transcription in vitro using phage t7 rna polymerase in the presence of guanosine 5'-phosphorothioate. the photoagent ... | 1990 | 1701142 |
| site-specific cleavage of rna by fe(ii).bleomycin. | bleomycin is an antitumor agent whose activity has long been thought to derive from its ability to degrade dna. recent findings suggest that cellular rna may be a therapeutically relevant locus. at micromolar concentrations, fe(ii)-bleomycin readily cleaved a bacillus subtilis trnahis precursor in a highly selective fashion, but escherichia coli trna(tyr) precursor was largely unaffected even under more forcing conditions. other substrates included an rna transcript encoding a large segment of t ... | 1990 | 1701259 |
| isolation of the second bacillus thuringiensis rna polymerase that transcribes from a crystal protein gene promoter. | a crystal protein gene of bacillus thuringiensis subsp. kurstaki hd-1-dipel is transcribed in vivo from two overlapping promoters that are activated at different times during sporulation. we reported earlier (k. l. brown and h. r. whiteley, proc. natl. acad. sci. usa 85:4166-4170, 1988) that an rna polymerase containing a sigma subunit with an apparent mr of 35,000 can transcribe in vitro from the promoter utilized from early to midsporulation. we now report the isolation of an rna polymerase co ... | 1990 | 1701426 |
| cloning of a promoter used by sigma h rna polymerase in bacillus subtilis. | the secondary rna polymerase sigma factor sigma h is essential for endospore development in bacillus subtilis. however, only a few promoters that are used by rna polymerase containing sigma h (e sigma h) have been identified. we used in vitro transcription of random cloned fragments of b. subtilis chromosomal dna to identify a promoter that is used by e sigma h. this promoter is active before the onset of sporulation. | 1990 | 1702397 |
| the bacillus subtilis small cytoplasmic rna gene and 'dnax' map near the chromosomal replication origin. | the bacillus subtilis small cytoplasmic rna (scrna) has an important, although not yet defined function in protein biosynthesis. here we describe the mapping of the single copy scrna gene and the flanking homolog to dnazx of escherichia coli, termed 'dnax'. the scrna gene region of a b. subtilis wild-type strain was marked with a cat gene and mapped by scoring chromosomal cotransformation rates of various mutant strains to chloramphenicol resistance and loss of the mutant phenotypes, respectivel ... | 1990 | 1703271 |
| purification and characterization of rnase p from clostridium sporogenes. | rnase p is a multi-subunit enzyme responsible for the accurate processing of the 5' terminus of all trnas. the rna subunit from clostridium sporogenes has been partially purified and characterized. the rna is approximately 400 nucleotides long and makes a precise endonucleolytic cleavage at the mature 5' terminus of trna. the rna requires moderate concentrations of mg2+ (20 mm) and relatively high concentrations of nh4cl (800 mm) for optimal activity. mn2+ effectively substitutes for mg2+ at 2 m ... | 1990 | 1704096 |
| a new defective phage containing a randomly selected 8 kilobase-pairs fragment of host chromosomal dna inducible in a strain of bacillus natto. | a new defective phage, designated pbnd8, was induced in bacillus natto strain iam1207 with bleomycin and mitomycin c. pbnd8 particles contained a randomly selected 8 kilobase-pairs (kbp) fragment of the host chromosomal dna. electron microscopy showed that pbnd8 has a small head with a complex tail structure like pbsx, a defective phage of bacillus subtilis 168. the pbnd8 head, however, is clearly smaller than that of pbsx which contains 13-kbp fragments of the host chromosomal dna. sds-polyacry ... | 1990 | 1704337 |
| triple post-transcriptional control. | the ermc gene confers resistance to mls antibiotics in a bacillus subtilis host. synthesis of the ermc gene product, a ribosomal rna methylase, is inducible by the addition of subinhibitory concentrations of erythromycin. regulation of ermc gene expression occurs at the post-transcriptional level in three ways: translational attenuation, translational autoregulation, and messenger rna stabilization. | 1990 | 1704997 |
| the rna component of rnase p from the archaebacterium haloferax volcanii. | rnase p, an endoribonuclease responsible for generating the mature 5' termini of trna precursors, is composed of both rna and protein. it has been demonstrated that the eubacterial rnase p rna will, under the appropriate reaction conditions, exhibit catalytic activity in vitro. evidence has not been obtained for catalytic activity by the rnas of eukaryotic rnase p enzymes. using a cdna probe prepared from rna copurifying with rnase p activity from the archaebacterium haloferax volcanii, we have ... | 1991 | 1706337 |
| catalytic rna: a nobel prize for small village science. | | 1990 | 1706622 |
| analysis of the conformational transitions of proteins by temperature-gradient gel electrophoresis. | temperature-gradient gel electrophoresis (tgge) is a technique for studying the structural transitions of nucleic acids and proteins. a temperature gradient is formed in a horizontal slab gel perpendicular to the direction of the electric field. whereas the principle of the tgge method has previously been applied to proteins, we describe in this report the systematic optimization of tgge as a routine technique for the quantitative analysis of conformational transitions in proteins. using alpha-a ... | 1990 | 1706658 |
| the importance of the 5'-region in regulating the stability of sdh mrna in bacillus subtilis. | the decay of the polycistronic bacillus subtilis sdh mrna was analysed using probes specific for each of the component cistrons, sdhc, sdha and sdhb. in exponentially growing cells, the entire sdh mrna seems to decay with an 'all or nothing' mechanism and with a uniform half-life of 2-3 min for all cistrons. in stationary-phase cells, the half-life of the 5'-part had dropped to about 0.6 min whereas that of the 3'-part was about 1.2 min. decay of sdh mrna was also measured in exponentially growi ... | 1990 | 1707123 |
| cloning and characterization of the mycobacterium leprae putative ribosomal rna promoter in escherichia coli. | the putative promoter region of the 16s ribosomal rna-encoding gene (rrna) of mycobacterium leprae was cloned and characterized in escherichia coli. a 932-bp haeiii restriction fragment, containing the 5' end of the 16s rrna gene and flanking upstream region, was cloned in front of a promoterless reporter gene in the shuttle vector, pmh109, to generate the plasmid, pya1101. this clone exhibits promoter activity both in gram-(e. coli) and gram+ (bacillus subtilis) bacteria. sequence analysis and ... | 1991 | 1707388 |
| enzymatic basis for hydrolytic versus phosphorolytic mrna degradation in escherichia coli and bacillus subtilis. | the rapid synthesis and breakdown of mrna in prokaryotes can impose a significant energy drain on these cells. previous in vivo studies [duffy, j. j., chaney, s. g. & boyer, p. d. (1972) j. mol. biol. 64, 565-579; chaney, s. g. & boyer, p. d. (1972) j. mol. biol. 64, 581-591] indicated that while rna turnover in escherichia coli was hydrolytic, it was nonhydrolytic in bacillus subtilis. here we provide an explanation for these observations based on enzymatic analysis of extracts of these two org ... | 1991 | 1707536 |
| isolation and characterization of lactococcus lactis subsp. lactis promoters. | dna fragments with promoter activity were isolated from the chromosome of lactococcus lactis subsp. lactis. for the isolation, a promoter probe vector based on the cat gene was constructed, which allowed direct selection with chloramphenicol in bacillus subtilis and l. lactis. four of the putative promoters (p1, p2, p10, and p21) were analyzed further by sequencing, mapping of the 5' end of the mrna, northern (rna blot) hybridization, and chloramphenicol acetyltransferase activity measurements. ... | 1991 | 1707605 |
| synthesis and properties of some peptide analogues of actinomycin d. | analogues of actinomycin d (amd) were synthesized in which amino acid replacements were made at various sites in the peptide moieties. these include (i) replacement of both n-methylvalines by n-methylleucine, (ii) replacement of both sarcosines by n-[2-(methoxycarbonyl)ethyl]glycine, and (iii) replacement of one or both d-valines by d-threonine. the purpose of replacements ii and iii was to ascertain the effect upon biological activity of introducing a new side chain which could be functionalize ... | 1991 | 1707976 |
| gene encoding two alkali-soluble components of the spore coat from bacillus subtilis. | we report the cloning and characterization of a gene called cotf from bacillus subtilis that encodes alkali-soluble polypeptides of 5 and 8 kda that are components of the spore coat. the 5- and 8-kda polypeptides are generated by proteolytic cleavage of the primary product of the cotf gene, which is 160 codons in length and is capable of encoding a polypeptide of 19 kda. amino acid sequence analysis indicates that the 5-kda species is derived from the nh2-terminal portion of the primary gene pro ... | 1991 | 1708381 |
| [application of microcarriers to bacillus subtilis culture]. | microcarriers, first applied to cell cultures. it was reported that microcarriers affected cell growth positively. in this study cytodex i microcarriers were used. because of their surface characteristics mammalian cells can easily attach to cytodex i microcarriers and grow well. b. subtilis cells also attached to microcarriers and grew well. in this study cytodex i microcarriers were used for productive bacterial growth. | 1990 | 1708441 |
| ionic channels induced by surfactin in planar lipid bilayer membranes. | surfactin is a lipopeptide produced by certain strains of bacillus subtilis and has potent surface activity. here, we present the first results showing that ion-conducting pores can be formed by surfactin in artificial lipid membranes. with a low aqueous concentration of surfactin (1 microm) and a restricted membrane area (5.10(-5) cm2) we observed conductance jumps that indicate the formation of individual ionic channels in the presence of k+, rb+, cs+, na+ or li+ chlorides. although for every ... | 1991 | 1709052 |
| functional organization and nucleotide sequence of the bacillus subtilis pyrimidine biosynthetic operon. | a 12.5-kilobase segment of bacillus subtilis chromosomal dna containing the entire pyrimidine biosynthetic (pyr) gene cluster has been cloned and sequenced. the sequenced dna has seven cistrons encoding the six enzymes of de novo pyrimidine nucleotide biosynthesis and two open reading frames of unknown function. based on the sequence and mapping of transcripts, the genes in this cluster appear to be transcribed on one large polycistronic message in the order orf1, pyrb, pyrc, pyraa, pyrab, orf2, ... | 1991 | 1709162 |
| effect of ermc leader region mutations on induced mrna stability. | induction of translation of the ermc gene product in bacillus subtilis occurs upon exposure to erythromycin and is a result of ribosome stalling in the ermc leader peptide coding sequence. another result of ribosome stalling is stabilization of ermc mrna. the effect of leader rna secondary structure, methylase translation, and leader peptide translation on induced ermc mrna stability was examined by constructing various mutations in the ermc leader region. analysis of deletion mutations showed t ... | 1991 | 1711026 |
| cloning, nucleotide sequence, and expression of the bacillus subtilis ans operon, which codes for l-asparaginase and l-aspartase. | l-aspartase was purified from bacillus subtilis, its n-terminal amino acid sequence was determined to construct a probe for the aspartase gene, and the gene (termed ansb) was cloned and sequenced. a second gene (termed ansa) was found upstream of the ansb gene and coded for l-asparaginase. these two genes were in an operon designated the ans operon, which is 80% cotransformed with the previously mapped asph1 mutation at 215 degrees. primer extension analysis of in vivo ans mrna revealed two tran ... | 1991 | 1711029 |
| role and expression of the bacillus subtilis rodc operon. | the role of the rodc operon in bacillus subtilis was investigated. the operon encodes two genes (rodd and rodc) necessary for the synthesis of the cell wall teichoic acid. transcription of this operon is responsive to levels of phosphate and to concentrations of magnesium ions in the growth medium. this regulation of mrna production corresponds to conditions that dictate the type of polymer that will be synthesized for the cell wall, i.e., teichoic or teichuronic acid. while the introduction of ... | 1991 | 1712357 |
| transcription initiation region of the srfa operon, which is controlled by the comp-coma signal transduction system in bacillus subtilis. | srfa is an operon required for the production of the lipopeptide antibiotic surfactin, competence development, and efficient sporulation in bacillus subtilis. the expression of srfa is induced after the end of exponential growth and is dependent on the products of late-growth regulatory genes comp, coma, and spo0k. to begin to understand the mechanism of srfa regulation, the srfa promoter region was identified and characterized. to examine srfa promoter activity, the srfa promoter was fused to l ... | 1991 | 1715856 |
| sequence and properties of comq, a new competence regulatory gene of bacillus subtilis. | the sequence and properties of the comq gene are described. comq was predicted to encode a 34,209-da protein, and the product of comq was shown to be required for the development of genetic competence. the apparent transcriptional initiation and termination sites of comq were mapped, and the location of a likely e sigma a promoter was inferred. the expression of comq was maximal early in growth and declined as the cells approached the stationary phase. this expression was not dependent on any of ... | 1991 | 1715859 |
| molecular analysis of the bacillus subtilis recf function. | recf resides between the dnan and gyrb genes of bacillus subtilis. the recf15 mutation results in replacement of a glutamate residue in the wild type with a lysine residue in the mutant recf protein. we investigated the in vivo regulation of recf using a transcriptional fusion to the xyle gene and assaying mrna production. we found that novobiocin leads to a four-fold induction in recf gene expression, but this is not observed in a gyrb mutant strain. enhancement of expression of the recf gene i ... | 1991 | 1716726 |
| site-specific cleavage by metal ion cofactors and inhibitors of m1 rna, the catalytic subunit of rnase p from escherichia coli. | the location of phosphate residues involved in specific centers for binding of metal ions in m1 rna, the catalytic rna subunit of rnase p from escherichia coli, was determined by analysis of induction of cleavage of rna by metal ions. at ph 9.5, mg2+ catalyzes cleavage of m1 rna at five principal sites. under certain conditions, mn2+ and ca2+ can each replace mg2+ as the cofactor in the processing of precursor trnas by m1 rna and p rna, the rna subunit of rnase p from bacillus subtilis. these ca ... | 1991 | 1718000 |
| [dependence of bacillus subtilis cell respiration on monovalent cations]. | nigericin, monensin, valinomycin + carbonyl-cyanide-m-chlorophenylhydrazone and gramicidin inhibit the respiration of bacillus subtilis cells incubated with nad-dependent substrates or succinate, but not with ascorbate + n,n,n',n'-tetramethyl-p- phenylene-diamine. the level of inhibition was decreased by potassium ions and, in a lower degree, by sodium or ammonium ions. the results obtained suggest that the respiration of bacillus subtilis depends on the presence of monovalent cations whose effe ... | 1991 | 1718449 |
| effects of monochlorophenols and p-chloroaniline on nucleic acid synthesis in microbial growth process. | | 1991 | 1718512 |
| long-range structure in ribonuclease p rna. | phylogenetic-comparative and mutational analyses were used to elucidate the structure of the catalytically active rna component of eubacterial ribonuclease p (rnase p). in addition to the refinement and extension of known structural elements, the analyses revealed a long-range interaction that results in a second pseudoknot in the rna. this feature strongly constrains the three-dimensional structure of rnase p rna near the active site. some rnase p rnas lack this structure but contain a unique, ... | 1991 | 1719634 |
| molecular cloning, structure, promoters and regulatory elements for transcription of the bacillus megaterium encoded regulon for xylose utilization. | the xyla and xylb genes of bacillus subtilis br151 encoding xylose isomerase and xylulokinase, respectively, were disrupted by gene replacement rendering the constructed mutant strain unable to grow on xylose as the sole carbon source. the bacillus megaterium encoded xyl genes were cloned by complementation of this strain to xylose utilization. the nucleotide sequence of about 4 kbp of the insertion indicates the presence of the xyla and xylb genes on the complementing plasmid. furthermore, a re ... | 1991 | 1719948 |
| ribosome hopping and translational frameshifting are inadequate alternatives to translational attenuation in cat-86 regulation. | the induction of cat-86 by chloramphenicol has been proposed to follow the translational attenuation model. in the absence of inducer, the cat-86 gene is transcribed but remains phenotypically unexpressed because the transcripts sequester the ribosome binding site for the cat coding sequence in a stable stem-loop structure, preventing translation initiation. the translational attenuation model proposes that the natural inducer, chloramphenicol, stalls a ribosome in the leader region of cat trans ... | 1991 | 1720771 |
| cloning, characterization and evolution of the bsufi restriction endonuclease gene of bacillus subtilis and purification of the enzyme. | the restriction endonuclease (r.bsufi) of bacillus subtilis recognizes the target dna sequence 5' ccgg. the r.bsufi gene was found in close proximity to the cognate m.bsufi gene, which had previously been characterized (1). cloning of the r.bsufi gene in e.coli was only possible with the m.bsufi mtase gene present on a compatible plasmid. the cloned r.bsufi gene was expressed in e. coli and restriction activity was observed in vivo and in vitro. the r.bsufi gene consists of 1185 bp, coding for a ... | 1991 | 1721700 |