Structure of SAP18: a ubiquitin fold in histone deacetylase complex assembly.
McCallum, S.A., Bazan, J.F., Merchant, M., Yin, J., Pan, B., de Sauvage, F.J., Fairbrother, W.J.(2006) Biochemistry 45: 11974-11982
- PubMed: 17002296 
- DOI: https://doi.org/10.1021/bi060687l
- Primary Citation of Related Structures:  
2HDE - PubMed Abstract: 
Signal transduction pathways are frequently found to repress transcription of target genes in the absence of stimulation and, conversely, to upregulate transcription in the presence of a signal. Transcription factors are central in this dual regulatory mechanism and widely use a generalized mechanism to repress transcription through recruitment of a Sin3-histone deacetylase (HDAC) complex to their binding sites on DNA. The protein SAP18 (Sin3-associated polypeptide of 18 kDa) has been shown to play a key role in gene-specific recruitment of the HDAC complex by a number of transcription factors including Gli, GAGA, and Bicoid. The solution structure of SAP18 reveals a ubiquitin-like fold with several large loop insertions relative to other family members. This fold supports the functional role of SAP18 as a protein-protein adapter module and provides insight for how SAP18 may bridge the Sin3-HDAC complex to transcription factors.
Organizational Affiliation: 
Department of Protein Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080-4990, USA.