Insertion of in-frame sequence tags into proteins using transposons

Several methods based on the use of transposons allow the efficient generat ion of relatively short (e.g., <35 residues) in-frame insertions in protein s. The analysis of such insertions has provided a simple means to identify sites that tolerate dramatic sequence changes without loss of function ("pe rmissive" sites) and to dissect protein structure-function relationships. I n addition, epitope and protease cleavage site "tags" introduced in such in sertions have made it possible to analyze the oligomerization state and tra nsmembrane topologies of several proteins. Finally, the DNA inserted by the se methods generally carries restriction sites which may facilitate the con struction of in-frame deletions and gene fusions encoding a variety of chim eric proteins. (C) 2000 Academic Press.