Marie-Anne O'Reilly

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Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been greatly expanded by gene duplication, the largest family(More)
Toxic shock syndrome (TSS) is a complex of generalized symptoms caused by a local staphylococcal infection, and a circulating toxin is thought to be involved. Indeed, nearly 100% of TSS isolates produce an exoprotein, TSSE, that is thought to have an aetiological role on the basis of positive animal tests (refs 1,2 and F. Quimby, personal communication) and(More)
To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximately 4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were predicted to be essential. The vast majority of essential(More)
Expression of the general stress regulon of Bacillus subtilis is controlled by the alternative transcription factor sigma(B), which is activated when cells encounter growth-limiting energy or environmental stresses. The RsbT serine-threonine kinase is required to convey environmental stress signals to sigma(B), and this kinase activity is magnified in vitro(More)
Insertion of the erythromycin-resistance transposon Tn551 into the Staphylococcus aureus chromosome at a site which maps between the purB and ilv loci has a pleiotrophic effect on the production of a number of extracellular proteins. Production of alpha, beta and delta hemolysin, toxic shock syndrome toxin (TSST-1) and staphylokinase was depressed about(More)
The transition state regulator AbrB functions as an activator, a repressor, and a preventer of gene expression in Bacillus subtilis. In this paper, we show that expression of abrB is growth phase dependent. Accumulation of abrB transcript is restricted to a short period spanning the transition between the lag and exponential phases of the growth cycle. The(More)
A common feature of development in most vertebrate models is the early segregation of the germ line from the soma. For example, in Xenopus and zebrafish embryos primordial germ cells (PGCs) are specified by germ plasm that is inherited from the egg; in mice, Blimp1 expression in the epiblast mediates the commitment of cells to the germ line. How these(More)
Mutants of Staphylococcus aureus which fail to express alpha-toxin (Hly), beta-toxin (Hlb), or both have been constructed by site-specific mutagenesis. The virulence of the mutants was compared with that of wild-type toxigenic strains by intramammary inoculation of lactating mice. A bovine strain, M60, and a laboratory strain, 8325-4, caused acute mastitis(More)
PBSX and skin are two unusual genetic elements resident on the Bacillus subtilis chromosome. PBSX is a phage-like element located at approximately 100 degrees which is induced by the SOS response and results in cell lysis with the release of phage-like particles. The phage particles contain bacterial chromosomal DNA and kill sensitive bacteria without(More)
The ykzB and ykoL genes encode two peptides, of 51 and 60 amino acids, the functions of which are unknown. The ykzB and tnrA genes are contiguous and transcribed divergently. Expression of ykzB and ykoL is induced by glutamate and is under the control of the TnrA global regulator of nitrogen utilization. TnrA regulated its own synthesis in glutamate minimal(More)