RING finger, HC subclass, found in recombination activating gene-1 (RAG-1) and similar proteins
RAG-1, also known as V(D)J recombination-activating protein 1, RING finger protein 74 (RNF74), or endonuclease RAG1, is the catalytic component of the RAG complex, a multiprotein complex that mediates the DNA cleavage phase during V(D)J recombination. RAG1 is a lymphoid-specific factor that mediates DNA-binding to conserved recombination signal sequences (RSS) and catalyzes DNA cleavage activities by introducing a double-strand break between the RSS and the adjacent coding segment. It also functions as an E3 ubiquitin-protein ligase that mediates monoubiquitination of histone H3, which is required for the joining step of V(D)J recombination. RAG-1 contains an N-terminal C3HC4-type RING-HC finger that mediates monoubiquitylation of histone H3, an adjacent C2H2-type zinc finger, and a nonamer binding (NBD) DNA-binding domain.
Conserved feature residue pattern:C C H C H C C C C
Evidence:
Structure:1RMD; Mus musculus RAG1 binds four Zn2+ ions through a novel zinc binuclear cluster that includes the RING-HC finger - View structure with Cn3D
Comment:C3HC4-type RING-HC finger consensus motif: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C, where X is any amino acid and the number of X residues varies in different fingers
Comment:A RING finger typically binds two zinc atoms, with its Cys and/or His side chains in a unique "cross-brace" arrangement.
Jiyao W et al.(2023). "The conserved domain database in 2023.",