(A) Domain structure of the DIAPH1 protein, with DFNA1 mutations shown in red. Numbering is based on isoform NP_005210.3, with complete amino acid sequences provided in Table S1. The gray box over the sequence alignment shows the assigned boundary of the DAD domain. The ‘FFC’ region of the protein contains the FH domains and the C-terminus, and the ‘NT’ region encompasses the rest. Abbreviations: GBD, GTPase binding domain; DID, Diaphanous inhibitory domain; FH, formin homology; DAD, Diaphanous autoinhibitory domain. (B) SDS-PAGE analysis of purified proteins, shown with Coomassie staining.