Insertion of IS1 into the rpsE gene for ribosomal protein S5 causes cold-sensitivity in Escherichia coli

Summary The nucleotide sequence of the rpsE gene for the ribosomal protein S5 of a mutant of E. coli showing cold-sensitive growth revealed the presence of an insertion sequence, IS1, near the 3-end of the gene. This mutant grows very slowly even at the permissive temperature (30°C). At temperatures below 20°C, its growth becomes negligible. It is likely that the presence of IS1 disturbs the continued translation of the polycistronic messenger RNA of the spc-operon from the point of IS1 insertion downwards, especially at the unfavorable temperatures.