6Y93

Crystal structure of the DNA-binding domain of the Nucleoid Occlusion Factor (Noc) complexed to the Noc-binding site (NBS)

Summary for 6Y93

• Entry DOI: 10.2210/pdb6y93/pdb
• Descriptor: Nucleoid occlusion protein, Noc Binding Site (NBS) (2 entities in total)
• Functional Keywords: chromosome segregation, chromosome maintenance, protein-dna recognition, evolution, dna-binding protein, dna binding protein
• Biological source: Bacillus subtilis (strain 168); More
• Total number of polymer chains: 4
• Total formula weight: 47115.75

Authors

Jalal, A.S.B.,Tran, N.T.,Stevenson, C.E.M.,Chan, E.,Lo, R.,Tan, X.,Noy, A.,Lawson, D.M.,Le, T.B.K. (deposition date: 2020-03-06, release date: 2020-08-05, Last modification date: 2024-01-24)

Primary citation

Jalal, A.S.B.,Tran, N.T.,Stevenson, C.E.,Chan, E.W.,Lo, R.,Tan, X.,Noy, A.,Lawson, D.M.,Le, T.B.K.
Diversification of DNA-Binding Specificity by Permissive and Specificity-Switching Mutations in the ParB/Noc Protein Family.
Cell Rep, 32:107928-107928, 2020

PubMed Abstract: Specific interactions between proteins and DNA are essential to many biological processes. Yet, it remains unclear how the diversification in DNA-binding specificity was brought about, and the mutational paths that led to changes in specificity are unknown. Using a pair of evolutionarily related DNA-binding proteins, each with a different DNA preference (ParB [Partitioning Protein B] and Noc [Nucleoid Occlusion Factor], which both play roles in bacterial chromosome maintenance), we show that specificity is encoded by a set of four residues at the protein-DNA interface. Combining X-ray crystallography and deep mutational scanning of the interface, we suggest that permissive mutations must be introduced before specificity-switching mutations to reprogram specificity and that mutational paths to new specificity do not necessarily involve dual-specificity intermediates. Overall, our results provide insight into the possible evolutionary history of ParB and Noc and, in a broader context, might be useful for understanding the evolution of other classes of DNA-binding proteins.

PubMed: 32698006
DOI: 10.1016/j.celrep.2020.107928

Experimental method

X-RAY DIFFRACTION (2.23 Å)