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The CTP-binding domain is disengaged from the DNA-binding domain in a cocrystal structure of Bacillus subtilis Noc-DNA complex.
- Source :
-
Journal of Biological Chemistry . Apr2023, Vol. 299 Issue 4, p1-9. 9p. - Publication Year :
- 2023
-
Abstract
- In Bacillus subtilis, a ParB-like nucleoid occlusion protein (Noc) binds specifically to Noc-binding sites (NBSs) on the chromosome to help coordinate chromosome segregation and cell division. Noc does so by binding to CTP to form large membrane-associated nucleoprotein complexes to physically inhibit the assembly of the cell division machinery. The sitespecific binding of Noc to NBS DNA is a prerequisite for CTP-binding and the subsequent formation of a membraneactive DNA-entrapped protein complex. Here, we solve the structure of a C-terminally truncated B. subtilis Noc bound to NBS DNA to reveal the conformation of Noc at this crucial step. Our structure reveals the disengagement between the Nterminal CTP-binding domain and the NBS-binding domain of each DNA-bound Noc subunit; this is driven, in part, by the swapping of helices 4 and 5 at the interface of the two domains. Site-specific crosslinking data suggest that this conformation of Noc-NBS exists in solution. Overall, our results lend support to the recent proposal that parS/NBS binding catalyzes CTP binding and DNA entrapment by preventing the reengagement of the CTP-binding domain and the DNA-binding domain from the same ParB/Noc subunit. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00219258
- Volume :
- 299
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 164000631
- Full Text :
- https://doi.org/10.1016/j.jbc.2023.103063