Oral Presentation 16th Asian Conference on Transcription 2019

CHD4 slides nucleosomes by decoupling entry – exit-side DNA translocation (1171)

Yichen Zhong 1 , Bishnu Prasad Paudel 2 3 , Daniel P Ryan 1 , Jason K K Low 1 , Charlotte Franck 1 , Karishma Patel 1 , Max J Bedward 1 , Richard J Payne 3 , Antoine M va Oijen 2 3 , Joel P Mackay 1
  1. University of Sydney, Darlington, NSW, Australia
  2. University of Wollongong, NSW, Australia
  3. Illawarra Health and Medical Research Institute, Wollongong, Australia

Chromatin remodellers convert the chemical energy of ATP hydrolysis to the mechanical movement of nucleosomal DNA relative to a histone octamer. The molecular basis for this activity is only partially resolved, and it is not clear if the mechanism is conserved among the four classes of remodelling enzyme. Of these enzymes, the least well understood family are the chromo-helicase domain (CHD) enzymes exemplified by CHD4, the remodelling component of the Nucleosome Remodelling and Deacetylase (NuRD) complex. Here, we use single-molecule assays to demonstrate that the flanking DNA enters and exits the nucleosome through two decoupled translocation processes, and the formation of a CHD4-nucleosome complex – even in the absence of nucleotide – is sufficient to prime the system. In combination with recent analyses of yeast remodelling enzymes, our data lead to a model for the mechanism of nucleosome sliding.