Figure 8.

BIRD/IDD recognition by the SHR‐SCR heterodimer. (A) BIRD/IDD transcription factors contain four conserved zinc fingers (ZFs) at the N‐terminal regions, with the first two (ZF1 and ZF2) of the C₂H₂ type ZF and the next two (ZF3 and ZF4) of the C₂ HC type. ZF1–3 mediates specific binding to DNAs of target genes. (B) The structure of the JKD‐SHR‐SCR complex. The SHR GRAS domain comprises the helical cap (magenta) and the α/β core (blue) and also the SCR GRAS domain comprises the helical cap (green) and the α/β core (cyan). The JKD ZF3 and ZF4 modules (orange) directly bound to SHR of the SHR‐SCR heterodimer. The groove formed by α4‐ and α7‐helies of the α/β core accommodates the ZF4 α‐helix.