H-NS can facilitate specific DNA-binding by RNA polymerase in AT-rich gene regulatory regions

Research output: Contribution to journalArticle


Colleges, School and Institutes


Extremely AT-rich DNA sequences present a challenging template for specific recognition by RNA polymerase. In bacteria, this is because the promoter −10 hexamer, the major DNA element recognised by RNA polymerase, is itself AT-rich. We show that Histone-like Nucleoid Structuring (H-NS) protein can facilitate correct recognition of a promoter by RNA polymerase in AT-rich gene regulatory regions. Thus, at the Escherichia coli ehxCABD operon, RNA polymerase is unable to distinguish between the promoter −10 element and similar overlapping sequences. This problem is resolved in native nucleoprotein because the overlapping sequences are masked by H-NS. Our work provides mechanistic insight into nucleoprotein structure and its effect on protein-DNA interactions in prokaryotic cells.


Original languageEnglish
Article numbere1003589
JournalPLoS Genetics
Issue number6
Publication statusPublished - 20 Jun 2013


  • DNA cleavage, DNA sequences, DNA transcription, Gene regulation, Immunoprecipitation, Primer extension, RNA extraction, RNA polymerase