Terrance J. Leighton

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The stability of postlogarithmic mRNA has been assessed in Bacillus subtilis during sporulation time periods. The appearance of refractile bodies, alkaline phosphatase synthesis, and total protein synthesis is controlled by mRNA which has an estimated half-life of less than 10 min. Inhibition of RNA synthesis at various times by rifampin addition or(More)
In the minimum path coloring problem, we are given a list of pairs of vertices of a graph. We are asked to connect each pair by a colored path. Paths of the same color must be edge disjoint. Our objective is to minimize the number of colors used. This problem was raised by Aggarwal et al [1] and Raghavan and Upfal [22] as a model for routing in all-optical(More)
The expression of many gene products required during the early stages of Bacillus subtilis sporulation is regulated by sinIR operon proteins. Transcription of sinIR from the P1 promoter is induced at the end of exponential growth. In vivo transcription studies suggest that P1 induction is repressed by the transition-state regulatory protein Hpr and is(More)
Our previous atomic force microscopy (AFM) studies successfully visualized native Bacillus atrophaeus spore coat ultrastructure and surface morphology. We have shown that the outer spore coat surface is formed by a crystalline array of approximately 11 nm thick rodlets, having a periodicity of approximately 8 nm. We present here further AFM ultrastructural(More)
Defined minimal media conditions were used to assess and subsequently enhance the production of subtilisin by genetically characterized Bacillus subtilis strains. Subtilisin production was initiated by the exhaustion or limitation of ammonium in batch and fed-batch cultures. Expression of the subtilisin gene (aprE) was monitored with a chromosomal(More)
We have utilized atomic force microscopy (AFM) to visualize the native surface topography and ultrastructure of Bacillus thuringiensis and Bacillus cereus spores in water and in air. AFM was able to resolve the nanostructure of the exosporium and three distinctive classes of appendages. Removal of the exosporium exposed either a hexagonal honeycomb layer(More)
We reported previously the cloning and sequence of the Bacillus subtilis infB gene which encodes the essential IF2 factor required for initiation of translation (K. Shazand, J. Tucker, R. Chiang, K. Stansmore, H. U. Sperling-Petersen, M. Grunberg-Manago, J. C. Rabinowitz, and T. Leighton, J. Bacteriol. 172:2675-2687, 1990). The location of the 5' border of(More)
We have shown previously that Spo0A∼P-dependent sinIR operon expression was substantially down-regulated in abrB null mutant backgrounds. In this report, we show that loss of function mutations in abrB also cause phosphorelay gene expression to be down regulated. abrB null mutations caused diminished vegetative growth-associated sporulation and resulted in(More)
Bacillus anthracis has four plasmid possible virulence genotypes: pXO1+/pXO2+, pXO1+/pXO2-, pXO1-/pXO2+ or pXO1-/pXO2-. Due to the lack of a specific chromosomal marker for B. anthracis, differentiation of the pXO1-/pXO2- form of B. anthracis from closely related Bacillus cereus group species is difficult. In this study, we evaluate the ability of sspE,(More)
The capability to image single microbial cell surfaces at nanometer scale under native conditions would profoundly impact mechanistic and structural studies of pathogenesis, immunobiology, environmental resistance, and biotransformation. Here, using in vitro atomic force microscopy, we have directly visualized high-resolution native structures of bacterial(More)