Initiation factor 1 (IF1) is an essential protein in Escherichia coli involved in the initiation step of protein synthesis. The protein level of IF1 increases when E. coli cells are subjected to cold shock, however, it remains unclear as to how this increase occurs. The infA gene encoding IF1 contains two promoters, the distal P1 and the proximal P2 promoter. In this study, we found that infA mRNA was greatly increased, and that this increase resulted from transcriptional activation of P1, not P2, during cold shock although stability of transcripts from both promoters concomitantly increased.

Wireless sensor networks are evolving from relatively undemanding applications to applications which have stronger requirements. The coordination of distributed entities and events requires time synchronization. Although a number of methods have been studied for WSNs, some applications require high precision time synchronization. Precision time synchronization enables a variety of extensions of applications. The IEEE 1588 precision time protocol (PTP) provides a standard method to synchronize devices in a network with sub-microsecond precision. This paper deals with precision time synchronization using IEEE 1588 over wireless sensor networks. Precision time synchronization using IEEE 1588 provides compatibility between heterogeneous systems in WSNs. This paper also presents experiments and performance evaluation of precision time synchronization in WSNs. Our result established a method for nodes in a network to maintain their clocks to within a 200 nanosecond offset from the reference clock of a master node.

To identify RNA motifs interacting with 5S rRNA, a systematic evolution of ligands by exponential enrichment experiment was applied. Some of the resulting RNA aptamers contained a consensus sequence similar to the sequence in the loop region of helix 89 of 23S rRNA. We show that the synthetic helix 89 RNA motif indeed interacted with 5S rRNA and that the region around loop B of 5S rRNA was involved in this interaction. These results suggest the presence of a novel RNA^RNA interaction between 23S rRNA and 5S rRNA which may play an important role in the ribosome function. ß 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

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