Xiaofeng Cao and colleagues report that the H3K27 demethylase REF6 binds directly to a specific DNA sequence through its Cys2His2 zinc-finger domains. They show that Arabidopsis thaliana mutants for REF6 exhibit defects in cotyledon separation, thereby linking sequence-specific H3K27me3 demethylation to organ boundary formation.
- Xia Cui
- Falong Lu
- Xiaofeng Cao
