Fig. 4
Construction and analyses of the IS1447 elements with a mutated slippage-prone region. a Potential frameshift window sequences of IS1447 mutants. The A9T-related sequences are highlighted in yellow. The putative reading frames and + 1 frameshift sites for OrfAB are underlined and indicated above the sequence, respectively. Three-nucleotide reading frame sequences were deleted from the wild-type IS1447 (A9T) to construct mutants A7 (A9T lacking AAT), A6 (A9T lacking AAA), A4 (A9T lacking A5T), A3 (A9T lacking A6), A1 (A9T lacking A8T), and A0 (A9T lacking A9); ∆5′ and ∆3′ indicate the mutants with deleted 5′ and 3′ codons to the A9T motif, which are gray highlighted. b Western blot analysis of IS1447 mutants using Anti-His6-tag antibody. M, protein standards, the molecular weights are shown to the left of the figure. c The predicted secondary structures of IS1447 mRNA sequences around the slippage-prone region. A stem-loop structure is predicted to include two A nucleotides of the A9U sequence (yellow highlighted). The RNA secondary structures were predicted by mfold web server (http://unafold.rna.albany.edu/?q=mfold/RNA-Folding-Form) [55]. d The consensus sequences of the slippage-prone region of IS1447-like TEs