Practice question

Bacterial genome partitioning analogous mitosis uses conserved tripartite system. Components include ParA ATPase Walker box, ParB DNA binding protein, centromere like DNA site parS. parS consists of short palindrome repeats 16 base pairs each bound specifically by ParB via helix turn helix domain, ParB CTPase forms focus spreading several kilobases forming partition complex that also loads SMC condensin MukBEF. ParA ATP dimer binds nonspecifically to nucleoid periphery, forming oscillating pattern. Interaction ParB triggers ATP hydrolysis releasing ParA allowing movement. Tripartite ParA ParB parS cassette found on chromosome near oriC for chromosome segregation in many bacteria Caulobacter, Vibrio, and on low copy plasmids P1, F for plasmid maintenance. Deletions increase plasmid loss and anucleate cells frequency drastically. System differs from divisome FtsZ FtsA cytokinesis, MinC MinD MinE division placement, MreB crescentin shape determination. Partition ensures each daughter cell inherits genetic material maintaining species continuity and antibiotic resistance plasmids dissemination stability without selection.