RING finger, H2 subclass, found in ubiquitin-protein ligase E3-alpha-3 (UBR3) and similar proteins
UBR3, also known as N-recognin-3, E3alpha-III, or zinc finger protein 650, is an E3 ubiquitin-protein ligase targeting the essential DNA repair protein APE1, also known as Ref-1, for ubiquitylation. It regulates cellular levels of APE1 and is required for genome stability. It also plays a regulatory role in sensory pathways, including olfaction. In Drosophila, UBR3 also regulates apoptosis by controlling the activity of Drosophila inhibitor of apoptosis protein 1 (DIAP1), which is required to prevent caspase activation. UBR3 contains an N-terminal ubiquitin-recognin (UBR) box, a C3H2C3-type RING-H2 finger, and a C-terminal UBR-specific autoinhibitory (UAIN) domain.
Comment:C3H2C3-type RING-H2 finger consensus motif: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-H-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.",