Outside a warm-blooded animal host, the enterobacterium Escherichia coli K-12 is also able to grow and survive in stressful nature. The major organic substance in nature is plant, but the genetic system of E. coli how to utilize plant-derived materials as nutrients is poorly understood. Here we describe the set of regulatory targets for uncharacterized IclR-family transcription factor YiaJ on the E. coli genome, using gSELEX screening system. Among a total of 18 high-affinity binding targets of YiaJ, the major regulatory target was identified to be the yiaLMNOPQRS operon for utilization of ascorbate from fruits and galacturonate from plant pectin. The targets of YiaJ also include the genes involved in the utilization for other plant-derived materials as nutrients such as fructose, sorbitol, glycerol and fructoselysine. Detailed in vitro and in vivo analyses suggest that L-ascorbate and α-D-galacturonate are the effector ligands for regulation of YiaJ function. These findings altogether indicate that YiaJ plays a major regulatory role in expression of a set of the genes for the utilization of plant-derived materials as nutrients for survival. PlaR was also suggested to play protecting roles of E. coli under stressful environments in nature, including the formation of biofilm. We then propose renaming YiaJ to PlaR (regulator of plant utilization). Bacteria constantly monitor environmental conditions, and respond for adaptation and survival by modulating the expression pattern of their genomes. Transcription, the major regulation step in gene expression, is carried out by a single species of RNA polymerase (RNAP). The intracellular concentration of RNAP core enzyme in growing Escherichia coli K-12 W3110 strain is about 2,000 molecules per genome, which is less than the total of about 4,500 genes on its genome 1,2. The expression pattern of a total of about 4,500 genes in its genome, however, can be modulated through alteration of the promoter selectivity of RNAP after interaction with two groups of the regulatory proteins, i.e., seven species of the promoter recognition subunit sigma 1,3,4 and about 300 species of the DNA-binding transcription factors (TFs) 5,6. Based on the protein structure of DNA-binding motifs, these TFs were classified into 54 families (5; TEC database [www.shigen.nig.ac.jp/ecoli/tec/]). Up to the present time, more than 80% of the estimated 300 TFs in E. coli K-12 have been linked to at least one regulatory target gene or operon in its genome. The search for regulatory targets of these TFs has been carried out in vivo using both the ordinary molecular genetic approaches and the modern methodologies such as transcriptome using DNA microarrays and chromatin immunoprecipitation (ChIP) approaches. Using only in vivo analyses, however, it is difficult to get the complete set of regulatory targets because the binding in vivo of test TFs to their DNA targets is interfered with by both approximately 300 species of co-existing TFs and a number of nucleoid-associated DNA-binding proteins 5. The regulato...

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This paper reports on a specific cognitive behavior often found when trying to understand a text not written in readers’ native language. Our research group conducted a questionnaire survey to examine Japanese readers’ cognitive behavior and awareness when reading English texts. We also conducted a factor analysis on this questionnaire to identify the behaviors often found when reading English. Participants were 56 Japanese students studying engineering at Chuo University. After reading the texts, a questionnaire consisting of 43 items was applied to the participants. We used exploratory factor analysis to identify the primary factors related to readers’ cognitive behavior and awareness when reading a non-native language. As a result of the analysis, mainly based on the highest contributing factors, it was suggested that readers may have made substitutions into Japanese, their own words, when reading the English texts. In other words, when reading a non-native language, the reader may read the texts by replacing them with their native language rather than comprehending it in that language. Based on the results of our experiment, it is expected that the research on the cognitive supporting systems may help readers to understand non-native languages quickly and smoothly.