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)
protein ARF1-B3 ABI3-B3 RAV1-B3 B3 structure derived by molecular model molecular model NMR B3 recognition sequence TGTCTC CATGCA CACCTG
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