Stepping on the condensation

Abstract

Molecular Biology Condensin complexes are molecular motors that extrude DNA loops in a highly conserved and adenosine triphosphate–dependent manner, essential for eukaryotic chromosome condensation during mitosis. Elbatsh et al. mutated condensin at two motor sites (AS1 and AS2). They found that mutating AS1 impairs the initiation of loop formation leading to hypocondensation, and mutating AS2 speeds up contraction of DNA and diminishes the formation of high-order, stable loop structures. AS1 and AS2 thus serve as the accelerator and brake of the condensin machine. Regulating these two opposite adenosine triphosphatase activities is important for controlling chromatin structure. Mol. Cell 10.1016/j.molcel.2019.09.020 (2019).