Inverted-repeat nucleotide sequences in Escherichia coli and Caulobacter crescentus.

Abstract

The nucleotide sequences of several prokaryotic insertion sequence (IS) elements have been determined (Ohtsubo and Ohtsubo 1978; Ghosal et al. 1979). Hybridization experiments and computer analysis of reported nucleotide sequences have shown that mature Escherichia coli ribosomal RNA (rRNA) contains sequences homologous to portions of IS elements IS1 and IS2 (Nisen and Shapiro 1979). Evidence has accumulated that suggests that IS elements can modulate gene expression at the DNA level, e.g., by promoting chromosomal rearrangements, providing promoters, or inducing polarity (Starlinger and Saedler 1976). The sequence homologies between IS elements and E. coli rRNA raise the possibility that they play an additional role.