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

Cell. 1998 Jul 24;94(2):239-49. doi: 10.1016/s0092-8674(00)81423-3.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Conserved Sequence*
  • Crystallography, X-Ray
  • DNA-Binding Proteins / chemistry*
  • Dimerization
  • Fungal Proteins / chemistry*
  • Histones / chemistry*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Folding
  • Saccharomyces cerevisiae Proteins*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • TATA-Binding Protein Associated Factors*
  • Transcription Factor TFIID
  • Transcription Factors / chemistry*
  • Transcription Factors, TFII / chemistry


  • DNA-Binding Proteins
  • Fungal Proteins
  • Histones
  • SPT3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • TAF11 protein, human
  • TAF13 protein, human
  • TATA-Binding Protein Associated Factors
  • Transcription Factor TFIID
  • Transcription Factors
  • Transcription Factors, TFII

Associated data

  • PDB/1BH8
  • PDB/1BH9