In vitro DNA-binding properties of VirB, the Shigella flexneri virulence regulatory protein

Sorcha Mckenna (1) , Christophe Beloin (1) , Charles J. Dorman (1)

1 Trinity College Dublin

The DNA-binding activity of the Shigella flexneri VirB transcription factor was studied in vitro. The protein was found to bind non-specifically to DNA, but showed preferential binding to VirB-dependent promoter sequences. DNA binding was contingent on the presence of an intact helix-turn-helix motif. While high molecular mass protein-DNA complexes were formed in both specific and non-specific interactions with DNA, mutant derivatives of VirB lacking a leucine zipper domain or a carboxyl-terminal-located oligomerisation domain formed discrete complexes, indicating that an ability to oligomerise on DNA was responsible for the formation of high molecular mass complexes by the wild-type protein.

Mots clés: Helix-turn-helix motif; Shigella flexneri; Leucine zipper; VirB protein; Transcription factor; Gene regulation; transcription factor; gene regulation; leucine zipper; helix-turn-helix motif

Domaines: Biochimie, Biologie Moléculaire; Bactériologie

Sorcha Mckenna, Christophe Beloin, Charles J. Dorman. In vitro DNA-binding properties of VirB, the Shigella flexneri virulence regulatory protein. FEBS Letters, 2003, 545 (2-3), pp.183-7. ⟨10.1016/S0014-5793(03)00524-6⟩. ⟨hal-03217885⟩