Free Download Regulatory RNAs in Prokaryotes eBook PDF

Free Download Regulatory RNAs in Prokaryotes eBook PDF

Free Download Regulatory RNAs in Prokaryotes eBook PDF RNA molecules play a central role in gene regulation in all three domains of life.  Regulatory RNAs were originally discovered in prokaryotes as early as 1967. Fundamental mechanisms of how these molecules exert their functions were first analyzed in bacteria long before small RNAs were discovered as regulatory molecules
in eukaryotes. Research on regulatory RNA in prokaryotes occurred in three major
phases.

The first phase started in 1967, when Hindley (1967) identified an RNA species,
later named 6S RNA, as a distinct and abundant RNA species in E. coli. In pioneering work four years later, its sequence and putative secondary structure were published (Brownlee, 1971). However, several decades passed before 6S RNA function in regulating RNA polymerase activity was determined (Wassarman and Storz2000)

Another enterobacterial regulatory RNA reported early on was the Spot 42
(spf) RNA (Ikemura and Dahlberg 1973). Discovering that the spf gene is regulated
by the cAMP–CRP system (Sahagan and Dahlberg 1979) and the phenotypic con-
sequences of its overexpression (Rice and Dahlberg 1982) suggested its functional
relevance. However, a biological role was determined almost 40 years later, when
its significant complementarity to the region around the start codon of the galK
gene was noticed and its role in discoordinating gene expression of the galETKM galactose operon became unraveled (Møller et al. 2002).

About the same time the first trans-acting regulatory RNAs were discovered, the
first regulatory cis-antisense RNAs were identified in bacteria. These cis-antisense
RNAs initially appeared to be a hallmark of extrachromosomal genetic elements,
bacteriophages, transposons, and plasmids, controlling their life cycle or copy number.

The first of these findings was the identification of antisense transcripts for the gene cro in bacteriophage λ (Spiegelman et al. 1972). This type of transcription  was confirmed for bacteriophage λ when observing that overexpression of the 77 nt
OOP antisense transcript leads to its codegradation with the cII mRNA (Krinke and Wulff 1987; Krinke and Wulff 1990; Krinke et al. 1991). By studying the plasmidborne RNA I, another extrachromosomally located cis-antisense RNA, many fundamental insights were gained early on. Among those discoveries was that RNA

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