A Combined Global and Local Approach to Elucidate Spatial Organization of the Mycobacterial ParB-parS Partition Assembly

• Published in: Biochemistry (Easton) Vol. 50; no. 11; pp. 1799 - 1807
• Main Authors: Chaudhuri, Barnali N, Gupta, Sayan, Urban, Volker S, Chance, Mark R, D’Mello, Rhijuta, Smith, Lauren, Lyons, Kelly, Gee, Jessica
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22.03.2011
• Subjects: 60 APPLIED LIFE SCIENCES; Bacterial Proteins - chemistry; Bacterial Proteins - metabolism; BASIC BIOLOGICAL SCIENCES; Centromere - metabolism; Chromosome Segregation; CHROMOSOMES; DNA, Bacterial - chemistry; DNA, Bacterial - metabolism; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - metabolism; MASS SPECTROSCOPY; MYCOBACTERIUM TUBERCULOSIS; Mycobacterium tuberculosis - genetics; Mycobacterium tuberculosis - metabolism; NEUTRON DIFFRACTION; PLASMIDS; Plasmids - genetics; Plasmids - metabolism; PROTEINS; SCATTERING; SEGREGATION; SHAPE; SYMMETRY; TOPOLOGY
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi1016759

Combining diverse sets of data at global (size, shape) and local (residue) scales is an emerging trend for elucidating the organization and function of the cellular assemblies. We used such a strategy, combining data from X-ray and neutron scattering with H/D-contrast variation and X-ray footprinting with mass spectrometry, to elucidate the spatial organization of the ParB-parS assembly from Mycobacterium tuberculosis. The ParB-parS participates in plasmid and chromosome segregation and condensation in predivisional bacterial cells. ParB polymerizes around the parS centromere(s) to form a higher-order assembly that serves to recruit cyto-skeletal ParA ATPases and SMC proteins for chromosome segregation. A hybrid model of the ParB-parS was built by combining and correlating computational models with experiment-derived information about size, shape, position of the symmetry axis within the shape, internal topology, DNA−protein interface, exposed surface patches, and prior knowledge. This first view of the ParB-parS leads us to propose how ParB spread on the chromosome to form a larger assembly.