Effect of transcription of yeast chromatin on DNA topology in vivo.

摘要: Coding regions of transcribed and non-transcribed genes typically differ in chromatin structure. However, it is not known what kind alterations nucleosome or structure these differences reflect. To determine whether changes topology accompany transcription, we introduced into yeast a multicopy plasmid bearing the gene coding for heat shock protein HSP26. The plasmid-borne assembled chromatin, induced by same manner as endogenous HSP26 gene. A small change linking number accompanies shock. This consistent with that previously reported thermal untwisting DNA equivalent magnitude to observed control plasmids which lack heat-shock response elements. These data indicate no stable alteration transcription Moreover, kinetics topoisomerase relaxes thermally torsional stress 1-5 min. We conclude if polymerase passage, recovery must take place within this time period.