Final answer:
The purpose of RAG-1 and RAG-2 proteins is to mediate V(D)J recombination. HMG proteins assist in regulating gene expression by facilitating transcription initiation.
Step-by-step explanation:
The purpose of RAG-1 and RAG-2 proteins is to mediate V(D)J recombination. This process involves rearranging DNA segments to create a diverse repertoire of antigen receptors in immune cells. The RAG proteins recognize specific DNA sequences and facilitate the recombination of gene segments that encode the variable regions of antibodies and T-cell receptors. HMG proteins, on the other hand, play a role in DNA bending and protein-DNA interactions. They assist in regulating gene expression by facilitating transcription initiation and promoting the formation of transcription initiation complexes.