Evolution of the RAG1-RAG2 locus: both proteins came from the same transposon

Biology Direct

Vladimir V Kapitonov¹  Eugene V Koonin¹ 

[1] National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA

关键词: Transib transposase;    Transib DNA transposons;    RAG1 and RAG2 proteins;    V(D)J recombination;    immune system;    genetics;    Molecular evolution;   

Others  :  1180714
DOI  :  10.1186/s13062-015-0055-8

 received in 2015-03-04, accepted in 2015-04-17,  发布年份 2015

【 摘 要 】

The RAG1 and RAG2 proteins are essential subunits of the V(D)J recombinase that is required for the generation of the enormous variability of antibodies and T-cell receptors in jawed vertebrates. It was demonstrated previously that the 600-aa catalytic core of RAG1 evolved from the transposase of the Transib superfamily transposons. However, although homologs of RAG1 and RAG2 genes are adjacent in the purple sea urchin genome, a transposon encoding both proteins so far has not been reported. Here we describe such transposons in the genomes of green sea urchin, a starfish and an oyster. Comparison of the domain architectures of the RAG1 homologs in these transposons, denoted TransibSU, and other Transib superfamily transposases provides for reconstruction of the structure of the hypothetical TransibVDJ transposon that gave rise to the VDJ recombinases at the onset of vertebrate evolution some 500 million years ago.

【 授权许可】

   
2015 Kapitonov and Koonin; licensee BioMed Central.

【 图 表 】

Figure 1.

Figure 2.