InterPro domain: IPR040909

This is a cysteine rich domain which contains four zinc-binding regions (binding five zinc ions) found in CHFR, an E3 ubiquitin-protein ligase [ 1 ]. CHFR interacts with Poly(ADP-ribose) (PAR) through a 20-amino acid PAR binding zinc finger region (PBZ) found at the C-terminal end of this cysteine-rich domain (i.e. the 4th region towards the C-terminal). CHFR lacking PBZ does not co-localize with nuclear PAR foci in interphase cells and cannot rescue antephase checkpoint function despite retaining autoubiquitination activity. Hence it has been suggested that the CHFR-PAR interaction is an important part of the antephase checkpoint and could form part of the checkpoint sensor for cellular stress and microtubule poisons or be required for proper localization of CHFR. The PBZ region of CHFR contains two adenine binding sites [ 2 ].

1. Chfr regulates a mitotic stress pathway through its RING-finger domain with ubiquitin ligase activity. Cancer Res. 62, 1797-801
2. Structural basis of poly(ADP-ribose) recognition by the multizinc binding domain of checkpoint with forkhead-associated and RING Domains (CHFR). J. Biol. Chem. 285, 39348-58