Supercoiled induced transition to the Z-DNA conformation affects the ability of a d(CG/GC)12 sequence to be organized into nucleosome-cores

摘要

Nucleosome-cores were reconstituted by the salt-dialysis method onto closed circular pDHg16 DNA which contains a d(CG/GC)₁₂ sequence. Alternating d(CG/GC)_n sequences form left-handed Z-DNA readily when contained in negatively supercoiled DNA. We have investigated the ability of the d(CG/GC)₁₂ sequence to be organized into nucleosome-cores when stabilized as Z-DNA through negative supercoiling. We have found that nucleosome assembly at the d(CG/GC)₁₂ insert is prevented when the sequence 1s stable in the Z-conformation but it is not affected at all when the sequence adopts the right-handed B-form.