This domain is found in eukaryotes, and is approximately 220 amino acids in length. It lies just upstream of the ankyrin-repeat region at the C terminus of BCL-6 corepressor proteins. The function of this domain is not known.
The RAWUL domain is found at the C terminus of poly-comb group RING finger proteins. It contains a variant ubiquitin-like fold with a distinct conserved surface region. The conserved surface found in this domain is responsible for interaction with Cbx members of the PRC1 (polycomb repression complex 1) and homodimer formation []. The RAWUL domain binds directly to PUFD, a domain on BCOR proteins (BCL6 corepressor). BCOR has emerged as an important player in development and health [].
This entry represents the minimal domain at the C terminus of BCOR (BCL6 corepressor) that is needed for binding specifically to some of the PCGF proteins (polycomb-group RING finger homologues). Because of the selective binding, this domain has been named PCGF Ub-like fold discriminator (PUFD). PUFD binds to the RAWUL (RING finger- and WD40-associated ubiquitin-like) domain of the particular PCGF, PCGF1. Polycomb group proteins form repressive complexes (PRC) that mediate epigenetic modifications of histones. In humans there are many different PCGF homologues whose functions all vary, but the direct binding partner of PCGF1 is BCOR. BCOR has emerged as an important player in development and health [].
E3 ubiquitin-protein ligase RING2 () mediates monoubiquitination of 'Lys-119' of histone H2A (H2AK119Ub) [], which is a specific tag for epigenetic transcriptional repression and participates in X chromosome inactivation of female mammals []. RING2 is a component of the PRC1 complex [], and other chromatin-associated Polycomb (PcG) complexes such as BCOR []. It is also a component of the MLL1/MLL complex [].
The PUFD (PCGF Ub-like fold discriminator) domain is found at the C terminus of BCOR (BCL6 corepressor), and binds to the RAWUL (RING finger- and WD40-associated ubiquitin-like) domain of the polycomb-group protein PCGF1 []. This domain is also found in BCORL1 (BCL6 corepressor-like), which also binds PCGF1 through its PUFD domain []. Like BCOR, BCORL1 functions as a corepressor [].
E3 ubiquitin-protein ligase RING1 () is one of the three E3 ubiquitin-protein ligases that mediate monoubiquitination of 'Lys-119' of histone H2A, which is a specific tag for repression of epigenetic transcription and particularly for inactivation of chromosome X of female mammals [, ]. RING1 is a component of the Polycomb group (PcG) multiprotein PRC1-like complex, the repressive BCOR complex [], and the the E2F6.com-1 complex in G0 phase []. RING1 has a RING-type zinc finger.E3 ubiquitin-protein ligase RING2 () mediates monoubiquitination of 'Lys-119' of histone H2A (H2AK119Ub) [], which is a specific tag for epigenetic transcriptional repression and participates in X chromosome inactivation of female mammals []. RING2 is a component of the PRC1 complex [], and other chromatin-associated Polycomb (PcG) complexes such as BCOR []. It is also a component of the MLL1/MLL complex [].This entry includes E3 ubiquitin-protein ligase RING1/RING2.
