Incorporation of chromosomal proteins HMG-14/ HMG-17 into nascent nucleosomes induces an extended chromatin conformation and enhances the utilization of active transcription complexes

Lothar Trieschmann, Pedro J. Alfonso, Massimo P. Crippa, Alan P. Wolffe, Michael Bustin

Research output: Contribution to journalArticle


The role of chromosomal proteins HMG-14 and HMG-17 in the generation of transcriptionally active chromatin was studied in a Xenopus laevis egg extract which supports complementary DNA strand synthesis and chromatin assembly. Chromosomal proteins HMG14/HMG-17 enhanced transcription from a chromatin template carrying a 5S rRNA gene, but not from a DNA template. The transcriptional potential of chromatin was enhanced only when these proteins were incorporated into the template during, but not after, chromatin assembly. HMG-14 and HMG-17 stimulate transcription by increasing the activity, and not the number, of transcribed templates. They unfold the chromatin template without affecting the nucleosomal repeat or decreasing the content of histone B4. We suggest that HMG-14/HMG-17 enhance transcription by inducing an extended conformation in the chromatin fiber, perhaps due to interactions with histone tails in nucleosomes. By disrupting the higher order chromatin structure HMG-14/HMG-17 increase the accessibility of target sequences to components of the transcriptional apparatus.

Original languageEnglish
Pages (from-to)1478-1489
Number of pages12
JournalEMBO Journal
Issue number7
Publication statusPublished - 1995



  • Active chromatin
  • Chromatin assembly
  • Chromosomal proteins
  • Transcription
  • Xenopus

ASJC Scopus subject areas

  • Cell Biology
  • Genetics

Cite this