The B3 DNA binding domain (DBD) is a highly conserved domain found exclusively in transcription factors (≥40 species) (Pfam PF02362) combined with other domains (InterPro: IPR003340). It consists of 100-120 residues, includes seven beta strands and two alpha helices that form a DNA-binding pseudobarrel protein fold (SCOP 117343); 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)
PDB: 1WID and PDB: 1YEL 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 Archived 2008-12-04 at the Wayback MachineKummerfeld SK, Teichmann SA (2006). "DBD: a transcription factor prediction database". Nucleic Acids Res. 34 (Database issue): D74–81. doi:10.1093/nar/gkj131. PMC 1347493. PMID 16381970. 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 Archived 2019-10-17 at the Wayback Machine, RAV, and ARF Archived 2019-10-17 at the Wayback Machine family at PlantTFDB:Plant Transcription Factor Database