The IS 200 /IS 605 Family and “Peel and Paste” Single-strand Transposition Mechanism

Abstract

ABSTRACT This chapter presents an analysis of the organization and distribution of the IS 200 /IS 605 family of insertion sequences (IS). Members of this family are widespread in both bacteria and archaea. They are unusual because they use obligatory single-strand DNA intermediates, which distinguishes them from classical IS. We summarize studies of the experimental model systems IS 608 (from Helicobacter pylori ) and IS Dra2 (from Deinococcus radiodurans ) and present biochemical, genetic, and structural data that describe their transposition pathway and the way in which their transposase (an HuH rather than a DDE enzyme) catalyzes this process. The transposition of IS 200 /IS 605 family members can be described as a “Peel-and-Paste” mechanism. We also address the probable domestication of IS 200 /IS 605 family transposases as enzymes involved in multiplication of repeated extragenic palindromes and as potential homing endonucleases in intron–IS chimeras.