Question

During site-specific recombination that occurs in an antibody gene, the protein(s) that catalyze(s) the joining of V and J domains to each other is/are

A. RAG1 and RAG2.

B. nonhomologous end-joining (NHEJ) proteins.

C. RecA.

D. RecBCD.

Answer 1

The proteins RAG1 and RAG2 catalyze the joining of V and J domains in an antibody gene during site-specific recombination, which is crucial for creating antibody diversity.

Step-by-step explanation:

During site-specific recombination in an antibody gene, the joining of V (Variable) and J (Joining) domains to each other is catalyzed by the proteins RAG1 and RAG2. This process is integral to the generation of immunoglobulin diversity, enabling B cells to produce a vast array of antibodies with different antigen-binding specificities. Site-specific recombination occurs during the maturation of B cells in the bone marrow and involves the random recombination of V and J segments (and D segments for the heavy chain), which forms the unique variable region of an antibody that can bind a specific antigen. After V(D)J recombination, further diversity is achieved through RNA processing where all but one V and J segment are spliced out.