Binary Fission in Bacteria

Abstract

Abstract Given a suitable environment, most free‐living prokaryotic cells (including bacteria) will grow continually until, on reaching a critical size, they divide into two equal‐sized parts in a process called binary fission. To be successful, this process requires the accurate duplication and partition of the chromosomes, and subsequent splitting of the cytoplasm precisely at the cell midpoint. The latter process, known as cytokinesis, often uses a large transmembrane protein machine that includes homologues of actin and tubulin as well as enzymes that synthesise and degrade specific portions of the cell wall. The placement of this machine is often regulated by negatively acting morphogen gradients. Once assembled, numerous accessory proteins respond to various inputs to regulate how and when the machine constricts and cells physically separate. Key Concepts: The timing of chromosome duplication in bacteria responds to cell growth rate and initiates at a specific location only once per cell cycle. Bacterial chromosomes are organised and condensed by DNA‐binding proteins, some of which are conserved from bacteria to humans. Bacterial cells use homologues of eukaryotic cytoskeletal proteins actin and tubulin to organise their growth and division. Morphogen gradients of negative spatial regulators help to position the cytokinetic ring in many bacteria. Recent advances in synthetic biology of bacterial cytokinesis are increasing our understanding of key components.