Figure 2.
Echinomycin inhibits synthesis from double-stranded but not single-stranded DNA templates. (a) Nicked calf thymus DNA was incubated in diluted Xenopus egg extract supplemented with [α-32P]dATP for 75 min, together with different concentrations of echinomycin. (b) Demembranated Xenopus sperm chromatin was incubated in Xenopus egg extract supplemented with [α-32P]dATP for 20 and 30 min, after which solvent or 6 µM echinomycin was added and reactions allowed to proceed to 60 min.