Philip Youngman
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View article: <i>Staphylococcus aureus</i> TargetArray: Comprehensive Differential Essential Gene Expression as a Mechanistic Tool To Profile Antibacterials
<i>Staphylococcus aureus</i> TargetArray: Comprehensive Differential Essential Gene Expression as a Mechanistic Tool To Profile Antibacterials Open
The widespread emergence of antibiotic-resistant bacteria and a lack of new pharmaceutical development have catalyzed a need for new and innovative approaches for antibiotic drug discovery. One bottleneck in antibiotic discovery is the lac…
View article: Genome‐wide analysis of the general stress response in <i>Bacillus subtilis</i>
Genome‐wide analysis of the general stress response in <i>Bacillus subtilis</i> Open
Bacteria respond to diverse growth‐limiting stresses by producing a large set of general stress proteins. In Bacillus subtilis and related Gram‐positive pathogens, this response is governed by the σ B transcription factor. To establish the…
View article: γ-Glutamyltransferase Is a <i>Helicobacter pylori</i> Virulence Factor but Is Not Essential for Colonization
γ-Glutamyltransferase Is a <i>Helicobacter pylori</i> Virulence Factor but Is Not Essential for Colonization Open
The contribution of glutamyl transpeptidase (GGT) (γ-glutamyltransferase [EC 2. 3. 2. 2]) to Helicobacter pylori virulence was investigated in piglets and mice using GGT-deficient isogenic strains. All animals became colonized. However, th…
View article: Mutational Analysis of Conserved Residues in the Putative DNA-Binding Domain of the Response Regulator Spo0A of <i>Bacillus subtilis</i>
Mutational Analysis of Conserved Residues in the Putative DNA-Binding Domain of the Response Regulator Spo0A of <i>Bacillus subtilis</i> Open
The Spo0A protein of Bacillus subtilis is a DNA-binding protein that is required for the expression of genes involved in the initiation of sporulation. Spo0A binds directly to and both activates and represses transcription from the promote…
View article: Spo0A directly controls the switch from acid to solvent production in solvent‐forming clostridia
Spo0A directly controls the switch from acid to solvent production in solvent‐forming clostridia Open
The spo0A genes of Clostridium beijerinckii NCIMB 8052 and Clostridium cellulolyticum ATCC 35319 were isolated and characterized. The C‐terminal DNA‐binding domains of the predicted products of spo0A from these two organisms, as well as 16…
View article: Tn<i>917-lac</i>mutagenesis of<i>Streptococcus mutans</i>to identify environmentally regulated genes
Tn<i>917-lac</i>mutagenesis of<i>Streptococcus mutans</i>to identify environmentally regulated genes Open
Previously, we demonstrated successful Tn917 mutagenesis of the oral pathogen Streptococcus mutans using pTV1-OK (Km(r), repATs), a temperature conditional replicative delivery vector carrying a lactococcal pWVO1Ts backbone. In this report…
View article: Crystallization of the regulatory and effector domains of the key sporulation response regulator Spo0A
Crystallization of the regulatory and effector domains of the key sporulation response regulator Spo0A Open
The key response-regulator gene of sporulation, spo0A, has been cloned from Bacillus stearothermophilus and the encoded protein purified. The DNA-binding and phospho-acceptor domains of Spo0A have been prepared by tryptic digestion of the …
View article: Expression of Listeriolysin O and ActA by Intracellular and Extracellular<i>Listeria monocytogenes</i>
Expression of Listeriolysin O and ActA by Intracellular and Extracellular<i>Listeria monocytogenes</i> Open
Listeria monocytogenes requires listeriolysin O (LLO) and ActA, the products of hly and actA , respectively, to establish a productive intracellular infection. LLO is essential for vacuolar lysis and entry into the cytosol, while ActA is r…
View article: A Homolog of CcpA Mediates Catabolite Control in <i>Listeria monocytogenes</i> but Not Carbon Source Regulation of Virulence Genes
A Homolog of CcpA Mediates Catabolite Control in <i>Listeria monocytogenes</i> but Not Carbon Source Regulation of Virulence Genes Open
Readily utilizable sugars down-regulate virulence gene expression in Listeria monocytogenes , which has led to the proposal that this regulation may be an aspect of global catabolite regulation (CR). We recently demonstrated that the metab…
View article: Regulation of <i>hly</i> Expression in <i>Listeria monocytogenes</i> by Carbon Sources and pH Occurs through Separate Mechanisms Mediated by PrfA
Regulation of <i>hly</i> Expression in <i>Listeria monocytogenes</i> by Carbon Sources and pH Occurs through Separate Mechanisms Mediated by PrfA Open
Expression of the PrfA-controlled virulence gene hly (encoding the pore-forming cytolysin listeriolysin) is under negative regulation by readily metabolized carbon sources in Listeria monocytogenes . However, the hyperhemolytic strain NCTC…
View article: Spo0A Mutants of <i>Bacillus subtilis</i> with Sigma Factor-Specific Defects in Transcription Activation
Spo0A Mutants of <i>Bacillus subtilis</i> with Sigma Factor-Specific Defects in Transcription Activation Open
The transcription factor Spo0A of Bacillus subtilis has the unique ability to activate transcription from promoters that require different forms of RNA polymerase holoenzyme. One class of Spo0A-activated promoter, which includes spoIIEp , …
View article: New genetic techniques for group B streptococci: high-efficiency transformation, maintenance of temperature-sensitive pWV01 plasmids, and mutagenesis with Tn917
New genetic techniques for group B streptococci: high-efficiency transformation, maintenance of temperature-sensitive pWV01 plasmids, and mutagenesis with Tn917 Open
Three techniques were developed to improve the genetic manipulation of group B streptococci (GBS). We first optimized a protocol for transformation of GBS by electroporation, which provided transformation efficiencies of 10(5) CFU/microgra…
View article: SpoIIE mutants of Bacillus subtilis comprise two distinct phenotypic classes consistent with a dual functional role for the SpoIIE protein
SpoIIE mutants of Bacillus subtilis comprise two distinct phenotypic classes consistent with a dual functional role for the SpoIIE protein Open
Mutations in the spoIIE locus of Bacillus subtilis block sporulation at the stage of asymmetric septation and prevent compartment-specific activation of the transcription factor delta F. Recent ultrastructural studies of spoIIE mutants led…
View article: Insertional mutagenesis and recovery of interrupted genes of Streptococcus mutans by using transposon Tn917: preliminary characterization of mutants displaying acid sensitivity and nutritional requirements
Insertional mutagenesis and recovery of interrupted genes of Streptococcus mutans by using transposon Tn917: preliminary characterization of mutants displaying acid sensitivity and nutritional requirements Open
New vectors were constructed for efficient transposon Tn917-mediated mutagenesis of poorly transformable strains of Streptococcus mutans(pTV1-OK) and subsequent recovery of interrupted genes in Escherichia coli (pT21delta2TetM). In this re…
View article: Identification of a Bacillus subtilis spo0H allele that is necessary for suppression of the sporulation-defective phenotype of a spo0A mutation
Identification of a Bacillus subtilis spo0H allele that is necessary for suppression of the sporulation-defective phenotype of a spo0A mutation Open
A mutation in Bacillus subtilis spo0A codon 97 suppressed the sporulation defect caused by the spo0A9V mutation. The suppressor activity of the codon 97 mutation was evident only in the presence of a novel spo0H allele. Our results suggest…
View article: Phosphorylation of Bacillus subtilis transcription factor Spo0A stimulates transcription from the spoIIG promoter by enhancing binding to weak 0A boxes
Phosphorylation of Bacillus subtilis transcription factor Spo0A stimulates transcription from the spoIIG promoter by enhancing binding to weak 0A boxes Open
Activation of the spoIIG promoter at the onset of sporulation in Bacillus subtilis requires the regulatory protein, Spo0A, which binds to two sites in the promoter, sites 1 and 2. Phosphorylation of Spo0A is essential for the initiation of…
View article: Evidence that the spoIIM gene of Bacillus subtilis is transcribed by RNA polymerase associated with sigma E
Evidence that the spoIIM gene of Bacillus subtilis is transcribed by RNA polymerase associated with sigma E Open
We have investigated the temporal and spatial regulation of spoIIM, a gene of Bacillus subtilis whose product is required for complete septum migration and engulfment of the forespore compartment during sporulation. The spoIIM promoter was…
View article: Spo0A controls the sigma A-dependent activation of Bacillus subtilis sporulation-specific transcription unit spoIIE
Spo0A controls the sigma A-dependent activation of Bacillus subtilis sporulation-specific transcription unit spoIIE Open
The spoIIE operon is a developmentally regulated transcription unit activated in the second hour of sporulation in Bacillus subtilis. Its promoter has an unusual structure, containing sequences which conform perfectly to the consensus for …
View article: Transcriptional activation of the Listeria monocytogenes hemolysin gene in Bacillus subtilis
Transcriptional activation of the Listeria monocytogenes hemolysin gene in Bacillus subtilis Open
The prfA gene of Listeria monocytogenes was recently reported to be required for expression of hly, which encodes a pore-forming hemolysin essential for pathogenicity (M. Leimeister-Wachter, C. Haffner, E. Domann, W. Goebel, and T. Chakrab…
View article: Novel mutations that alter the regulation of sporulation in Bacillus subtilis
Novel mutations that alter the regulation of sporulation in Bacillus subtilis Open
Sporulation in Bacillus subtilis is a complex developmental process that occurs in response to nutrient deprivation. To identify components of the mechanism that allows cells to monitor their nutritional status and to understand how this s…
View article: xylE functions as an efficient reporter gene in Streptomyces spp.: use for the study of galP1, a catabolite-controlled promoter
xylE functions as an efficient reporter gene in Streptomyces spp.: use for the study of galP1, a catabolite-controlled promoter Open
We describe the development of a convenient and sensitive reporter gene system for Streptomyces spp. based on the use of a promoterless copy of the xylE gene of Pseudomonas putida. The xylE gene product is a catechol dioxygenase, which con…
View article: Genetic evidence that RNA polymerase associated with sigma A factor uses a sporulation-specific promoter in Bacillus subtilis.
Genetic evidence that RNA polymerase associated with sigma A factor uses a sporulation-specific promoter in Bacillus subtilis. Open
The construction of allele-specific suppressor mutations has enabled us to demonstrate that a sporulation-specific transcription unit in Bacillus subtilis, the spoIIG operon, is transcribed by a form of RNA polymerase associated with sigma…
View article: Temporal and spatial control of the mother-cell regulatory gene spoIIID of Bacillus subtilis.
Temporal and spatial control of the mother-cell regulatory gene spoIIID of Bacillus subtilis. Open
Gene expression during endospore formation in Bacillus subtilis is compartmentalized between the mother-cell and forespore chambers of the sporangium, which follow separate pathways of cellular differentiation. The earliest acting regulato…
View article: The promoter for a sporulation gene in the spoIVC locus of Bacillus subtilis and its use in studies of temporal and spatial control of gene expression
The promoter for a sporulation gene in the spoIVC locus of Bacillus subtilis and its use in studies of temporal and spatial control of gene expression Open
We have identified the transcription start site and regulatory region governing the expression of a sporulation gene in the spoIVC locus of Bacillus subtilis. Efficient expression and developmental regulation of this gene was controlled fr…
View article: Genetic Analysis of <i>Bacillus subtilis spo</i> Mutations Generated by Tn<i>917</i>-Mediated Insertional Mutagenesis
Genetic Analysis of <i>Bacillus subtilis spo</i> Mutations Generated by Tn<i>917</i>-Mediated Insertional Mutagenesis Open
Mutations that cause sporulation defects (spo mutations) often identify developmentally regulated transcription units or genes whose products are required for the expression of sporulation-specific regulons. We report here the isolation, g…
View article: Construction and properties of Tn917-lac, a transposon derivative that mediates transcriptional gene fusions in Bacillus subtilis.
Construction and properties of Tn917-lac, a transposon derivative that mediates transcriptional gene fusions in Bacillus subtilis. Open
A derivative of Tn917 was constructed, referred to as Tn917-lac, which is capable of generating fusions that connect the transcripts of Bacillus subtilis chromosomal genes to the coding sequence of the lacZ gene of Escherichia coli. Two in…
View article: Complementation of<i>npf</i>mutations in diploid amoebae of<i>Physarum polycephalum</i>: the basis for a general method of complementation analysis at the amoebal stage
Complementation of<i>npf</i>mutations in diploid amoebae of<i>Physarum polycephalum</i>: the basis for a general method of complementation analysis at the amoebal stage Open
Summary Haploid amoebae of Physarum polycephalum may form plasmodia by crossing, a sexual process that involves cellular and nuclear fusions, or by selfing, an asexual process in which the development of a single amoeba into a plasmodium m…
View article: Streptococcus plasmid pAM alpha 1 is a composite of two separable replicons, one of which is closely related to Bacillus plasmid pBC16
Streptococcus plasmid pAM alpha 1 is a composite of two separable replicons, one of which is closely related to Bacillus plasmid pBC16 Open
A tetracycline resistance plasmid of Streptococcus faecalis, pAM alpha 1, is shown to contain two independent sets of replication functions, separated from each other on either side by short (300- to 400-base-pair) sequences of homology. T…
View article: Genetic transposition and insertional mutagenesis in Bacillus subtilis with Streptococcus faecalis transposon Tn917.
Genetic transposition and insertional mutagenesis in Bacillus subtilis with Streptococcus faecalis transposon Tn917. Open
The Streptococcus faecalis transposon Tn917 was introduced into Bacillus subtilis by transformation of competent cells with the plasmid pAM alpha 1::Tn917 and was tested for transposition activity by selection for insertions into the tempe…
View article: TWO MULTIALLELIC MATING COMPATIBILITY LOCI SEPARATELY REGULATE ZYGOTE FORMATION AND ZYGOTE DIFFERENTIATION IN THE MYXOMYCETE <i>PHYSARUM POLYCEPHALUM</i>
TWO MULTIALLELIC MATING COMPATIBILITY LOCI SEPARATELY REGULATE ZYGOTE FORMATION AND ZYGOTE DIFFERENTIATION IN THE MYXOMYCETE <i>PHYSARUM POLYCEPHALUM</i> Open
The mating of Physarum polycephalum amoebae, the ultimate consequence of which is a "plasmodium," was recently shown to be governed by two compatibility loci, matA (or mt) and matB (DEE1 978; YOUNGMAeNt aZ. 1979), We present evidence that …