Megadalton chromatin remodelers: common principles for versatile functions

Area of Science:

• Molecular biology
• Structural biology
• Epigenetics

Background:

• ATP-dependent chromatin remodelers are essential macromolecular machines that regulate nucleosome arrangement and composition in eukaryotic genomes.
• Understanding their structure and mechanism is key to deciphering gene regulation and cellular function.

Purpose of the Study:

• To review recent breakthroughs in understanding ATP-dependent chromatin remodelers.
• To highlight structural and mechanistic principles, particularly for SWI/SNF and INO80/SWR1 complexes.

Main Methods:

• Cryo-electron microscopy (cryo-EM) has provided high-resolution structural insights.
• Analysis of conserved architectural components (motor, rotor, stator, grip) and molecular circuitry.

Main Results:

• Cryo-EM has yielded unprecedented high-resolution structures of all four chromatin remodeler families.
• A conserved architecture suggests a unifying mechanism for nucleosome reconfiguration via stepwise DNA translocation.
• A nuclear actin module framework explains allosteric regulation.

Conclusions:

• Chromatin remodelers act as programmable hubs integrating genetic and epigenetic information.
• Their function is dynamically regulated by the cell's physiological state.
• Emerging structural data provides a mechanistic basis for their diverse roles in genome regulation.