Fig. 3. Minimum dimerization domain in ADAR protein. (A) Schematic representation of Adar deletions expressed in yeast as LexA fusion proteins. Terminal amino acid residue numbers are indicated. All the truncated proteins that retained the N-terminus expressed as LexA fused proteins interacted with full-length ADAR expressed as an AD fusion protein. A weak interaction was detected when the two dsRBDs were expressed as independent domains; blue colour appeared after 7–8 h incubation and is indicated as (–/+), strong interaction with blue colour after 20 min incubation is indicated as (++), and no interaction at any time incubation is indicated as (–). (B) Positive protein–protein interactions between ADAR and truncated ADAR proteins were detected as blue β-galactosidase activity by filter lift assay after 20 min. The amino acid residues encoding the truncated ADAR proteins are indicated. The black frame highlights the ΔN-ADAR mutant.