Insertions of palindromic DNA sequences into the J-F intercistronic region of bacteriophage φX174 interfere with normal phage growth

摘要: Abstract The effect of hairpin (cruciform) size on the regulation gene expression was investigated by cloning a series palindromic sequences into non-essential J-F intercistronic region bacteriophage φX174 ins6 genome. Genetic stability insert sequence and its growth efficiency phage used as an initial measure biological consequence insertions. Multimers increasing BamHI linker C-C-G-G-A-T-C-C-G-G were inserted PvuII site parental strain ins6. largest that could be constructed maintained in genome had stem length 22 base-pairs loop four nucleotides (linker tetramer). However, this structure proved to disadvantageous rapidly deleted from Trimer inserts more stable, but eventually also. Monomer dimer inserts, though genetically decreased judged competitive experiments measurements burst size. physical formation these hairpins shown restriction digests single-stranded DNA with HpaII. We argue secondary structures form vivo, at least polycistronic mRNAs, responsible for observed defects.