This is a C2-H2 zinc-finger domain closely resembling the classical TFIIIA-type zinc-finger, CX3FX5LX2-3H, despite having a valine and a tyrosine at the core instead of a phenylalanine and a leucine, hence CX3VX1LX2YX2H. The structure, nevertheless, contains the characteristic two-stranded beta-sheet and alpha-helix of a classical zinc-finger. The domain binds one zinc and, in complex with the zinc-RING-finger domain, helps to stabilise the whole of the dimerisation region of recombination activating protein 1 (RAG1) [1]. The function of the whole is to bind double-stranded DNA.

1: Crystal structure of the RAG1 dimerization domain reveals multiple zinc-binding motifs including a novel zinc binuclear cluster. Bellon SF, Rodgers KK, Schatz DG, Coleman JE, Steitz TA; Nat Struct Biol. 1997;4:586-591. PMID:9228952