transposases

Genes called transposons in the single-celled pond-dwelling organism Oxytricha produce cell proteins known as transposases.

Junk DNA | Impact Lab 2009

Then, when no longer needed, the organism cleverly erases the transposases from its genetic material, paring its genome to a slim 5 percent of its original load.

Junk DNA | Impact Lab 2009

But now you can almost hear the ID folks sneering the in background “how very fortunate that there was a proto Ig molecule for the transposases to jump into, such a molecule would be functionless and could not evolve itself”.

Stuck on you, biological Velcro and the evolution of adaptive immunity - The Panda's Thumb 2006

But as we have seen, by the time the transib transposases inserted themselves into the proto-immunoglobulin gene, these molecules had hundreds of millions of years adaptation to an immune function already.

Stuck on you, biological Velcro and the evolution of adaptive immunity - The Panda's Thumb 2006

A series of careful investigations and elegant experiments has shown that the rearranging part of the variable domain is due to horizontal transfer and incorporation of transib transposases into the immunoglobulin gene.

Stuck on you, biological Velcro and the evolution of adaptive immunity - The Panda's Thumb 2006

Figure 1 Alignment of conserved regions in Transib transposases and RAG1 Click on the figure to see a larger version from the original paper

The Revenge of Calvin and Hobbes - The Panda's Thumb 2005

RAGs find their long-lost family of transposases 1.

The Revenge of Calvin and Hobbes - The Panda's Thumb 2005

A decade after the discovery of VDJ recombination the responsible enzymes, RAG1 and RAG2, were identified, and lo and behold their genes had a funny look about them: just like transposases, they were almost devoid of introns, and mapped right next to each other in the genome transposons need to “travel light”, and cannot carry excess DNA as they hop around.

The Revenge of Calvin and Hobbes - The Panda's Thumb 2005

They started from the observation of a low, borderline significant sequence similarity between a portion of RAG1 and certain transposases of the Transib family.

The Revenge of Calvin and Hobbes - The Panda's Thumb 2005

What they found was that 10 motifs were very highly conserved between RAG1 proteins from various species and Transib transposases.

The Revenge of Calvin and Hobbes - The Panda's Thumb 2005

Transposases are enzymes that power the movement of ‘jumping genes’ — ‘selfish’ bits of DNA that hop around the genome to propagate themselves.

Powerful CRISPR system inserts whole gene into human DNA Elie Dolgin 2025