The bacterial chromosome: architecture and action of bacterial SMC and SMC-like complexes

• Published in: FEMS microbiology reviews Vol. 38; no. 3; pp. 380 - 392
• Main Authors: Nolivos, Sophie, Sherratt, David
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.05.2014; Oxford University Press; Wiley-Blackwell
• Subjects: Architecture; Bacteria; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; chromosome; chromosome organization; chromosome segregation; Chromosomes; Chromosomes, Bacterial - chemistry; Chromosomes, Bacterial - metabolism; cohesin; condensin; Life Sciences; Other; Review; SMC; SMC; condensin; cohesin; chromosome organization; chromosome segregation; chromosome
• ISSN: 0168-6445; 1574-6976; 1574-6976
• DOI: 10.1111/1574-6976.12045

Abstract Structural Maintenance of Chromosomes (SMC) protein complexes are found in all three domains of life. They are characterized by a distinctive and conserved architecture in which a globular ATPase ‘head’ domain is formed by the N- and C-terminal regions of the SMC protein coming together, with a c. 50-nm-long antiparallel coiled-coil separating the head from a dimerization ‘hinge’. Dimerization gives both V- and O-shaped SMC dimers. The distinctive architecture points to a conserved biochemical mechanism of action. However, the details of this mechanism are incomplete, and the precise ways in which this mechanism leads to the biological functions of these complexes in chromosome organization and processing remain unclear. In this review, we introduce the properties of bacterial SMC complexes, compare them with eukaryotic complexes and discuss how their likely biochemical action relates to their roles in chromosome organization and segregation. By reviewing the properties of SMC complexes in all three domains of life, we assess their likely common biochemical mechanism of action and propose how this might relate to the functions of bacterial SMC complexes in chromosome segregation and chromosome organization. By reviewing the properties of SMC complexes in all three domains of life, we assess their likely common biochemical mechanism of action and propose how this might relate to the functions of bacterial SMC complexes in chromosome segregation and chromosome organization.