7OL9

Crystal structure of C-terminally truncated Bacillus subtilis nucleoid occlusion protein (Noc) complexed to the Noc-binding site (NBS)

Summary for 7OL9

• Entry DOI: 10.2210/pdb7ol9/pdb
• Descriptor: Nucleoid occlusion protein, DNA (5'-D(*TP*AP*TP*TP*TP*CP*CP*CP*GP*GP*GP*AP*AP*AP*TP*A)-3') (2 entities in total)
• Functional Keywords: chromosome segregation, chromosome maintenance, protein-dna recognition, dna-binding protein, dna binding protein
• Biological source: Bacillus subtilis (strain 168); More
• Total number of polymer chains: 4
• Total formula weight: 68936.24

Authors

Jalal, A.S.B.,Lawson, D.M.,Le, T.B.K. (deposition date: 2021-05-19, release date: 2022-03-09, Last modification date: 2024-02-07)

Primary citation

Sukhoverkov, K.V.,Jalal, A.S.B.,Ault, J.R.,Sobott, F.,Lawson, D.M.,Le, T.B.K.
The CTP-binding domain is disengaged from the DNA-binding domain in a cocrystal structure of Bacillus subtilis Noc-DNA complex.
J.Biol.Chem., 299:103063-103063, 2023

PubMed 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 site-specific binding of Noc to NBS DNA is a prerequisite for CTP-binding and the subsequent formation of a membrane-active 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 N-terminal 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.

PubMed: 36841481
DOI: 10.1016/j.jbc.2023.103063

Experimental method

X-RAY DIFFRACTION (2.9 Å)