This domain is found in plant RCD1, SRO and TAF4 proteins, hence its name of RST. It is required for interaction with multiple plant transcription factors. Radical-Induced Cell Death1 (RCD1) is an important regulator of stress and hormonal and developmental responses in Arabidopsis thaliana, as is its closest homolog, SRO1 - Similar To RCD-One1. TBP-Associated Factor 4 (TAF4) and TAF4-b are components of the transcription initiation factor complex TFIID.