SUMMARYIn plants, the ERF/EREBP family of transcriptional regulators plays a key role in adaptation to various biotic and abiotic stresses. These proteins contain a conserved AP2 DNA-binding domain and several uncharacterized motifs. Here, we describe a short motif, termed 'EDLL', that is present in AtERF98/TDR1 and other clade members from the same AP2 sub-family. We show that the EDLL motif, which has a unique arrangement of acidic amino acids and hydrophobic leucines, functions as a strong activation domain. The motif is transferable to other proteins, and is active at both proximal and distal positions of target promoters. As such, the EDLL motif is able to partly overcome the repression conferred by the AtHB2 transcription factor, which contains an ERF-associated amphiphilic repression (EAR) motif. We further examined the activation potential of EDLL by analysis of the regulation of flowering time by NF-Y (nuclear factor Y) proteins. Genetic evidence indicates that NF-Y protein complexes potentiate the action of CONSTANS in regulation of flowering in Arabidopsis; we show that the transcriptional activation function of CONSTANS can be substituted by direct fusion of the EDLL activation motif to NF-YB subunits. The EDLL motif represents a potent plant activation domain that can be used as a tool to confer transcriptional activation potential to heterologous DNA-binding proteins.

Turkey deli meat was the source of a large multistate outbreak of listeriosis. Investigation of this outbreak helped guide policy changes designed to prevent future L. monocytogenes contamination of ready-to-eat meat and poultry products.

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Between November 1998 and December 2000, the Centers for Disease Control and Prevention screened samples from 263 outbreaks of gastroenteritis in the United States and identified 3 that were associated with rotavirus among adults. Rotaviruses from each outbreak were further characterized by reverse-transcription polymerase chain reaction. Surprisingly, all specimens were of serotype G2, a strain that is, as determined by high-stringency hybridization analysis, genetically distinct in all 11 gene segments from the other common rotavirus strains in circulation. The unusual coincidence of identification of only G2 strains in these 3 outbreaks of rotavirus gastroenteritis among adults is similar to results from other studies, in which G2 strains were found in association with more-severe disease in children than other rotavirus serotypes and in association with outbreaks of diarrhea among adults in Japan. Although rotavirus infections in adults are relatively uncommon, which indicates that good overall protective immunity exists, the predominance of G2 strains in outbreaks that have occurred in adults suggests that natural immunity to more common strains does not always provide adequate heterotypic immunity to G2 strains. For the rotavirus vaccines under development, special attention may need to be paid to protection against G2 strains.