Base sequence discrimination by zinc-finger DNA-binding domains

摘要: ZINC fingers1,2 constitute important eukaryotic DNA-binding domains, being present in many transcription factors3–5. The Cys2/His2zinc-finger class has conserved motifs of 28–30 amino acids which are usually as tandem repeats1,2. structure a Cys2/His2zinc finger been determined by nuclear magnetic resonance6, but details its interaction with DNA were not established. Here we identify governing specificity using vitro directed mutagenesis guided similarities between the zinc fingers factors Spl (ref. 7) and Krox-20 8). is serum-inducible activator8,9 possibly involved regulation hindbrain development10; it contains three similar to those (refs 7, 8, 11) binds 9-base-pair target sequence related that 9). Our results show each spans nucleotides indicate two positions for base-pair selectivity. Modelling molecular graphics suggests these residues could bind directly bases other acid–base contacts also possible.