Speaker
Description
The way chromosomes are spatially organized influences their biological functions. Cells orchestrate the action of various molecules toward organizing their chromosomes: chromosome-associated proteins and the surrounding “free” molecules often referred to as crowders. Chain molecules like chromosomes can be entropically condensed in a crowded medium. A number of recent experiments showed that the presence of the protein H-NS enhances the entropic compaction of bacterial chromosomes by crowders. Using a coarse-grained computational model, we discuss the physical effects on bacterial chromosomes H-NS and crowders bring about. In this discussion, a H-NS dimer is modeled as a mobile binder with two binding sites, which can bind to a chromosome-like polymer with characteristic binding energy. Using the model, we will clarify the relative role of biomolecular crowding and H-NS in condensing a bacterial chromosome, offering quantitative insights into recent chromosome experiments. In particular, they shed light on the nature and degree of crowder and H-NS synergetics: while the presence of crowders enhances H-NS binding to a bacterial chromosome, the presence of H-NS makes crowding effects more efficient, suggesting two-way synergetics in condensing the chromosome.
| Keyword-1 | computational modeling |
|---|---|
| Keyword-2 | chromosome organization |
