Specific binding of a protein to a novel DNA element in the cyanobacterial small heat-shock protein gene

Kouji Kojima, Hitoshi Nakamoto

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


Previously, it was shown that transcription of the small heat-shock protein gene, hspA, from the thermophilic cyanobacterium Synechococcus vulcanus is transiently heat-inducible at a vegetative promoter that lacks any known regulatory DNA elements. A novel regulatory mechanism that suppresses the expression of hspA under non-heat-shock condition has been postulated. In this study, it is demonstrated that a protein(s) in the extract of unstressed cells of the thermophilic cyanobacterium Thermosynechococcus elongatus, a cyanobacterium closely related to S. vulcanus, specifically binds to a 5′-untranslated region of the hspA gene. An AT-rich imperfect inverted-repeat sequence (ACAAgcAAA-TTTagTTGT) as a target for a putative DNA-binding protein has been identified. The DNA-binding activity in the cell as well as in the cell extract was lost much more quickly at a heat-shock temperature than a normal growth temperature. In a cell, the activity was restored within 45 min after a heat-shock by the heat-induced synthesis and stabilization of a DNA-binding protein. It is proposed that the inverted repeat is a specific target for a DNA-binding protein and that it plays a role in the regulation of the cyanobacterial hspA gene expression.

Original languageEnglish
Pages (from-to)616-624
Number of pages9
JournalBiochemical and biophysical research communications
Issue number3
Publication statusPublished - 2002
Externally publishedYes


  • Cyanobacterium
  • DNA binding protein
  • Inverted repeat
  • Repressor
  • Small heat-shock protein
  • Thermophile
  • Thermosynechococcus elongatus

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Specific binding of a protein to a novel DNA element in the cyanobacterial small heat-shock protein gene'. Together they form a unique fingerprint.

Cite this