SHORTINTERNODE/STYLISH proteins are a highly redundant family of transcriptional activators targeting genes that mediate auxin biosynthesis. AtSTY1 interacts with a promoter element ACTCTA(C/A) in several genes related to auxin biosynthesis, YUC4, YUC8, ORCA3, and ORA59. Arabidopsis thaliana has nine members of the SHI/STY family that have a 43-amino acid RING-like zinc finger domain, and a more C-terminal domain, similar in size, the IGGH domain, which is responsible for intrafamily homo/hetero-dimerization that may be necessary for some of the proteins' functions (PMID:20154152).