A New Twist: Molecular Machines Loop and Twist Chromosomes

2024-12-17

Scientists have discovered a new function of the molecular motors that shape our chromosomes: SMC proteins not only form long loops in DNA but also significantly twist the DNA during loop formation. Published in Science Advances, the research reveals that SMC proteins introduce a left-handed twist of 0.6 turns in each DNA loop extrusion step. This twisting action is conserved across species, observed in both human and yeast cells, highlighting its evolutionary importance. This finding enhances our understanding of chromosome structure and function and provides insights into developmental diseases like cohesinopathies.