Figure 5From: Using BAC transgenesis in zebrafish to identify regulatory sequences of the amyloid precursor protein gene in humansThe DNA binding domain common to members of zebrafish E4BP4 or Forkhead (Fkd) families were each expressed in E. coli, partially purified under non-denaturing conditions, and tested for specific binding to their recognition sequences identified in and around the zebrafish appb gene. Panel A: E4BP4 protein, indicated below each lane in μg, added to Fkd probe (f), lanes 1–3, or the E4BP4 probe (e), lanes 4–8. Panel B: Fkd protein, indicated below each lane in μg, added to Fkd probe (f), lanes 1–4, or E4BP4 probe (e), lanes 5–7. Panel C: E4BP4 protein binding to probes (a through f) spanning upstream E4BP4 sites (a-d), E4BP4 site in intron 1 enhancer (e), and Fkd site in intron enhancer (f). E4BP4 protein used in each lane (μg) is indicated on right. Probes (b-d) correspond to cluster of three E4BP4 sites at −31 kb.Back to article page