Yet, scientists weren't convinced that RAG1 and RAG2 together make up a complete transposase, in large part because the proteins don't now seem to reinsert the clipped DNA into another stretch of DNA, as the enzymes normally do.
Both groups mixed together RAG1, RAG2, a DNA sequence nestled between the recombination sequences recognized by the two proteins, and a loop of target DNA.
An increase in the molecular weight of that circular DNA strand provided clear proof that RAG1 and RAG2 had all the skills of a true transposase.
Researchers now hope to determine whether RAG1 and RAG2 can carry out their cut-and-paste activities inside living cells.
He and Gellert would also like to understand in more detail how RAG1 and RAG2 together perform VDJ recombination and, in the test-tube system at least, both cut and paste DNA.
Scientists continue to wonder where the transposon that originally employed RAG1 and RAG2 came from.
Found in all jawed vertebrates, from sharks to humans, the RAG1 and RAG2 genes explain why higher animals have complex immune systems, including a first and second line of defence against invading pathogens.
Some 450 million years ago, Agrawal's research suggested, a bit of jumping genetic material, containing the RAG1 and RAG2 genes, infected an early jawed vertebrate such as a primitive shark.
This cut-and-paste process depends on the RAG1 and RAG2 genes.