Impact of cytosolic crowders on the morphology of bacterial chromosomes

Abstract

The bacterial chromosome forms a distinct membraneless organelle, the nucleoid, which occupies approximately 1/4-th of the total cell volume. There are at least four physical and chemical mechanisms identified that can play a major role in the chromosome organization: DNA supercoiling, cross-linking of DNA segments due to NAPs, active loop formation by SMC proteins, and macromolecular crowding due to various proteins, ribosomes, etc. floating in the cytosol. Recent experimental studies on E. coli elaborated the role of macromolecular crowding on chromosome organization.