The B3 DNA binding domain (DBD) is a highly conserved domain found exclusively in transcription factors (≥40 species) () combined with other domains (). It consists of 100-120 residues, includes seven beta strands and two alpha helices that form a DNA-binding pseudobarrel protein fold (); it interacts with the major groove of DNA.

B3 families

In Arabidopsis thaliana, there are three main families of transcription factors that contain B3 domain:

• ARF (Auxin Response Factors)

• ABI3 (ABscisic acid Insensitive3)

• RAV (Related to ABI3/VP1)

and are only known NMR solution phase structures of the B3 DNA Binding Domain.

Related proteins

The N-terminal domain of restriction endonuclease EcoRII; the C-terminal domain of restriction endonuclease BfiI possess a similar DNA-binding pseudobarrel protein fold.

See also

• Restriction endonuclease EcoRII

• Auxin

• Abscisic acid

References

External links

• DBD database of predicted transcription factors Uses a curated set of DNA-binding domains to predict transcription factors in all completely sequenced genomes

• Classification in the "Transcription factors" table according to the Transfac database.

• Database of Arabidopsis Transcription Factors

• B3 , RAV, and ARF family at PlantTFDB:Plant Transcription Factor Database