ParABS system

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The parABS system is a broadly conserved molecular mechanism for plasmid partitioning and chromosome segregation in bacteria. Originally identified as a genetic element required for faithful partitioning of low-copy-number plasmids, it consists of three components: the ParA ATPase, the ParB DNA-binding protein, and the cis-acting parS sequence. The parA and parB genes are typically found in the same operon, with parS elements located within or adjacent to this operon. Collectively, these components function to ensure accurate partitioning of plasmids or whole chromosomes between bacterial daughter cells prior to cell division. [1]

Mechanism

Based on chromatin immunoprecipitation (ChIP) experiments, ParB has the ability to bind not only to high-affinity parS sites but also to adjacent nonspecific DNA, a behavior known as "spreading". [2] [3] [4] [5] The ParB-DNA complex is thought to be translocated by a Brownian ratchet mechanism involving the ParA ATPase: ParA binds DNA nonspecifically in its ATP-bound state but much more weakly in its ADP-bound state. [6] [7] The ParB-DNA complex binds to ATP-bound ParA, [8] stimulating its ATPase activity and its dissociation from DNA. In this way, the ParB-DNA complex can be translocated by chasing a receding wave. [9] This translocation mechanism has been observed by fluorescence microscopy both in vivo and more recently in vitro with purified components. [10] [11] [12] [13]

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References

  1. ↑ Surtees, JA; Funnell, BE (2003). Plasmid and chromosome traffic control: how ParA and ParB drive partition. Vol. 56. pp. 145–80. doi:10.1016/s0070-2153(03)01010-x. ISBN   9780121531560. PMID   14584729.{{cite book}}: |journal= ignored (help)
  2. ↑ Rodionov, O; Lobocka, M; Yarmolinsky, M (Jan 22, 1999). "Silencing of genes flanking the P1 plasmid centromere". Science. 283 (5401): 546–9. Bibcode:1999Sci...283..546R. doi:10.1126/science.283.5401.546. PMID   9915704.
  3. ↑ Murray, H; Ferreira, H; Errington, J (Sep 2006). "The bacterial chromosome segregation protein Spo0J spreads along DNA from parS nucleation sites". Molecular Microbiology. 61 (5): 1352–61. doi:10.1111/j.1365-2958.2006.05316.x. hdl: 11449/701 . PMID   16925562. S2CID   17530813.
  4. ↑ Breier, AM; Grossman, AD (May 2007). "Whole-genome analysis of the chromosome partitioning and sporulation protein Spo0J (ParB) reveals spreading and origin-distal sites on the Bacillus subtilis chromosome". Molecular Microbiology. 64 (3): 703–18. doi: 10.1111/j.1365-2958.2007.05690.x . PMID   17462018.
  5. ↑ Sanchez, A; Cattoni, DI; Walter, JC; Rech, J; Parmeggiani, A; Nollmann, M; Bouet, JY (2015). "Stochastic Self-Assembly of ParB Proteins Builds the Bacterial DNA Segregation Apparatus". Cell Systems. 1 (2): 163–73. doi: 10.1016/j.cels.2015.07.013 . PMID   27135801.
  6. ↑ Bouet, JY; Ah-Seng, Y; Benmeradi, N; Lane, D (2007). "Polymerization of SopA partition ATPase: regulation by DNA binding and SopB". Molecular Microbiology. 63 (2): 468–81. doi: 10.1111/j.1365-2958.2006.05537.x . PMID   17166176.
  7. ↑ Castaing, JP; Bouet, JY; Lane, D (2008). "F plasmid partition depends on interaction of SopA with non-specific DNA". Molecular Microbiology. 70 (4): 1000–11. doi: 10.1111/j.1365-2958.2008.06465.x . PMID   18826408. S2CID   26612131.
  8. ↑ Bouet, JY; Funnell, BE (1999). "P1 ParA interacts with the P1 partition complex at parS and an ATP-ADP switch controls ParA activities". EMBO J. 18 (5): 1415–24. doi:10.1093/emboj/18.5.1415. PMC   1171231 . PMID   10064607.
  9. ↑ Walter, JC; Dorignac, J; Lorman, V; Rech, J; Bouet, JY; Nollmann, M; Palmeri, J; Parmeggiani, A; Geniet, F (2017). "Surfing on protein waves: proteophoresis as a mechanism for bacterial genome partitioning". Physical Review Letters. 119 (28101): 028101. arXiv: 1702.07372 . Bibcode:2017PhRvL.119b8101W. doi:10.1103/PhysRevLett.119.028101. PMID   28753349. S2CID   6762277.
  10. ↑ Ptacin, JL; Lee, SF; Garner, EC; Toro, E; Eckart, M; Comolli, LR; Moerner, WE; Shapiro, L (Aug 2010). "A spindle-like apparatus guides bacterial chromosome segregation". Nature Cell Biology. 12 (8): 791–8. doi:10.1038/ncb2083. PMC   3205914 . PMID   20657594.
  11. ↑ Ringgaard, S; van Zon, J; Howard, M; Gerdes, K (Nov 17, 2009). "Movement and equipositioning of plasmids by ParA filament disassembly". Proceedings of the National Academy of Sciences of the United States of America. 106 (46): 19369–74. Bibcode:2009PNAS..10619369R. doi: 10.1073/pnas.0908347106 . PMC   2775997 . PMID   19906997.
  12. ↑ Hwang, LC; Vecchiarelli, AG; Han, YW; Mizuuchi, M; Harada, Y; Funnell, BE; Mizuuchi, K (May 2, 2013). "ParA-mediated plasmid partition driven by protein pattern self-organization". The EMBO Journal. 32 (9): 1238–49. doi:10.1038/emboj.2013.34. PMC   3642677 . PMID   23443047.
  13. ↑ Vecchiarelli, AG; Hwang, LC; Mizuuchi, K (Apr 9, 2013). "Cell-free study of F plasmid partition provides evidence for cargo transport by a diffusion-ratchet mechanism". Proceedings of the National Academy of Sciences of the United States of America. 110 (15): E1390–7. Bibcode:2013PNAS..110E1390V. doi: 10.1073/pnas.1302745110 . PMC   3625265 . PMID   23479605.
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