Human TAF(II)28 and TAF(II)18 interact through a histone fold encoded by atypical evolutionary conserved motifs also found in the SPT3 family.
Birck, C., Poch, O., Romier, C., Ruff, M., Mengus, G., Lavigne, A.C., Davidson, I., Moras, D.(1998) Cell 94: 239-249
- PubMed: 9695952 
- DOI: https://doi.org/10.1016/s0092-8674(00)81423-3
- Primary Citation of Related Structures:  
1BH8, 1BH9 - PubMed Abstract: 
Determination of the crystal structure of the human TBP-associated factor (hTAF(II))28/hTAF(II)18 heterodimer shows that these TAF(II)s form a novel histone-like pair in the TFIID complex. The histone folds in hTAF(II)28 and hTAF(II)18 were not predicted from their primary sequence, indicating that these TAF(II)s define a novel family of atypical histone fold sequences. The TAF(II)18 and TAF(II)28 histone fold motifs are also present in the N- and C-terminal regions of the SPT3 proteins, suggesting that the histone fold in SPT3 may be reconstituted by intramolecular rather than classical intermolecular interactions. The existence of additional histone-like pairs in both the TFIID and SAGA complexes shows that the histone fold is a more commonly used motif for mediating TAF-TAF interactions than previously believed.
Organizational Affiliation: 
Institut de Génétique et de Biologie, Moléculaire et Cellulaire, CNRS/INSERM/ULP, Illkirch, C.U. de Strasbourg, France.