Publications by authors named "Joe E Grissom"

We analyzed the transcriptome of Escherichia coli K-12 by strand-specific RNA sequencing at single-nucleotide resolution during steady-state (logarithmic-phase) growth and upon entry into stationary phase in glucose minimal medium. To generate high-resolution transcriptome maps, we developed an organizational schema which showed that in practice only three features are required to define operon architecture: the promoter, terminator, and deep RNA sequence read coverage. We precisely annotated 2,122 promoters and 1,774 terminators, defining 1,510 operons with an average of 1.

View Article and Find Full Text PDF

Bacterial transcriptional networks consist of hundreds of transcription factors and thousands of promoters. However, the true complexity of transcription in a bacterial pathogen and the effect of the environments encountered during infection remain to be established. We present a simplified approach for global promoter identification in bacteria using RNA-seq-based transcriptomic analyses of 22 distinct infection-relevant environmental conditions.

View Article and Find Full Text PDF
Article Synopsis
  • A spontaneous mutant of Escherichia coli K-12, strain MG1655 (E. coli MG1655*), was isolated from streptomycin-treated mice and has enhanced colonization traits compared to the wild type.
  • The mutant exhibits faster growth on various carbon sources and is nonmotile due to a deletion in the flhD gene.
  • Genomic analyses indicate that the improved colonization ability is linked to the increased expression of catabolic genes, leading to better carbon source utilization and a larger population in the intestine.
View Article and Find Full Text PDF

Whole-genome expression profiling revealed Escherichia coli MG1655 genes induced by growth on mucus, conditions designed to mimic nutrient availability in the mammalian intestine. Most were nutritional genes corresponding to catabolic pathways for nutrients found in mucus. We knocked out several pathways and tested the relative fitness of the mutants for colonization of the mouse intestine in competition with their wild-type parent.

View Article and Find Full Text PDF