BEN domain (IPR018379)
Short name: BEN_domain
The BEN domain is found in diverse proteins including:
- SMAR1 (Scaffold/Matrix attachment region-binding protein 1; also known as BANP), a tumour-suppressor MAR-binding protein that down-regulates Cyclin D1 expression by recruiting HDAC1-mSin3A co-repressor complex at Cyclin D1 promoter locus; SMAR1 is the target of prostaglandin A2 (PGA2) induced growth arrest [PMID: 16166625, PMID: 17726044].
- NAC1, a novel member of the POZ/BTB (Pox virus and Zinc finger/Bric-a-bracTramtrack Broad complex), but which varies from other proteins of this class in that it lacks the characteristic DNA-binding motif [PMID: 17945361].
- Mod(mdg4) isoform C, the modifier of the mdg4 locus in Drosophila melanogaster (Fruit fly), where mdg4 encodes chromatin proteins which are involved in position effect variegation, establishment of chromatin boundaries, nerve path finding, meiotic chromosome pairing and apoptosis [PMID: 15094203]. Trans-splicing of Mod(mdg4) produces at least 26 transcripts.
- E5R protein from Chordopoxvirus virosomes, which is found in cytoplasmic sites of viral DNA replication [PMID: 10854161].
- Several proteins of polydnaviruses.
The BEN domain is predicted to function as an adaptor for the higher-order structuring of chromatin, and recruitment of chromatin modifying factors in transcriptional regulation. It has been suggested to mediate protein-DNA and protein-protein interactions during chromatin organisation and transcription. The presence of BEN domains in a poxviral early virosomal protein and in polydnaviral proteins also suggests a possible role in the organisation of viral DNA during replication or transcription. They are generally linked to other globular domains with functions related to transcriptional regulation and chromatin structure, such as BTB, C4DM, and C2H2 fingers [PMID: 18203771].
This domain is predicted to form an all-alpha fold with four conserved helices. Its conservation pattern reveals several conserved residues, most of which have hydrophobic side-chains and are likely to stabilise the fold through helix-helix packing [PMID: 18203771].