Send to

Choose Destination
Structure. 2002 May;10(5):701-13.

Tandem DNA recognition by PhoB, a two-component signal transduction transcriptional activator.

Author information

Institut de Biologia Molecular de Barcelona, CSIC, Jordi Girona, 18-26, E-08034 Barcelona, Spain.


PhoB is a signal transduction response regulator that activates nearly 40 genes in phosphate depletion conditions in E. coli and closely related bacteria. The structure of the PhoB effector domain in complex with its target DNA sequence, or pho box, reveals a novel tandem arrangement in which several monomers bind head to tail to successive 11-base pair direct-repeat sequences, coating one face of a smoothly bent double helix. The protein has a winged helix fold in which the DNA recognition elements comprise helix alpha 3, penetrating the major groove, and a beta hairpin wing interacting with a compressed minor groove via Arg219, tightly sandwiched between the DNA sugar backbones. The transactivation loops protrude laterally in an appropriate orientation to interact with the RNA polymerase sigma(70) subunit, which triggers transcription initiation.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center