−1 Frameshifting at a CGA AAG Hexanucleotide Site Is Required for Transposition of Insertion Sequence IS <i>1222</i>

Abstract

The discovery of programmed -1 frameshifting at the hexanucleotide shift site CGA_AAG, in addition to the classical X_XXY_YYZ heptanucleotide shift sequences, prompted a search for instances among eubacterial insertion sequence elements. IS1222 has a CGA_AAG shift site. A genetic analysis revealed that frameshifting at this site is required for transposition.