Hypothesis: hyperstructures regulate initiation in Escherichia coli and other bacteria.
Hyperstructures or modules have been proposed to constitute a level of organisation intermediate between macromolecules and whole cells. In this model of intracellular organisation, hyperstructures compete and collaborate for existence within the membrane and cytoplasm. Those directly involved in the cell cycle include initiation, replication and division hyperstructures based on DnaA, SeqA and the 2-minute cluster, respectively. During the run-up to initiation, the mass to DNA ratio increases and, we contend, differential gene expression leads to some hyperstructures becoming more active and stable than others. This results in a drop in the diversity of hyperstructures, some of which release DnaA as they dissociate, and a DnaA-initiation hyperstructure forms. Subsequent DNA replication and cell division generate different daughter cells containing different hyperstructures. This has the advantage of increasing the phenotypic diversity of the population. In developing this model, we also invoke hyperstructures in the partitioning of origins of replication.
Norris
Vic
V
Laboratoire des processus intégratifs cellulaires, UPRESA CNRS 6037, faculté des sciences et techniques, université de Rouen, 76821 cedex, Mont-Saint-Aignan, France. vjn@univ-rouen.fr
Demarty
Maurice
M
Raine
Derek
D
Cabin-Flaman
Armelle
A
Le Sceller
Loïs
L
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D001665:Binding Sites; D002453:Cell Cycle / Q000502:physiology; D019295:Computational Biology; D004261:DNA Replication / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D005798:Genes, Bacterial
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria