Nucleosome flipping drives selectivity and processivity of histone exchange by SWR1
ORAL · Invited
Abstract
The SWR1 chromatin remodelling complex is responsible for depositing the evolutionarily conserved H2A.Z–H2B histone dimer into chromatin. We developed single-molecule FRET assays that probe the interaction between SWR1 and its nucleosome substrate.
We show that SWR1 is able to flip a nucleosome between two states. By flipping the nucleosome, SWR1 can orient either H2A–H2B histone dimer towards the ATPase motor, priming it for exchange.
CryoEM analysis shows different SWR1-nucleosome complexes, indicating how SWR1 can flip a nucleosome. Overall, our data reveal a new mechanism by which SWR1 can proofread dimer identities within nucleosomes, hinting at a processive mechanism of dimer exchange.
We show that SWR1 is able to flip a nucleosome between two states. By flipping the nucleosome, SWR1 can orient either H2A–H2B histone dimer towards the ATPase motor, priming it for exchange.
CryoEM analysis shows different SWR1-nucleosome complexes, indicating how SWR1 can flip a nucleosome. Overall, our data reveal a new mechanism by which SWR1 can proofread dimer identities within nucleosomes, hinting at a processive mechanism of dimer exchange.
–
Presenters
-
Paul Girvan