Structural highlights
Function
PARB_CAUVN Involved in chromosome partition. Localize to both poles of the predivisional cell following completion of DNA replication. Binds to the DNA origin of replication.[1]
Publication Abstract from PubMed
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.
Diversification of DNA-Binding Specificity by Permissive and Specificity-Switching Mutations in the ParB/Noc Protein Family.,Jalal ASB, Tran NT, Stevenson CE, Chan EW, Lo R, Tan X, Noy A, Lawson DM, Le TBK Cell Rep. 2020 Jul 21;32(3):107928. doi: 10.1016/j.celrep.2020.107928. PMID:32698006[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Mohl DA, Gober JW. Cell cycle-dependent polar localization of chromosome partitioning proteins in Caulobacter crescentus. Cell. 1997 Mar 7;88(5):675-84. PMID:9054507
- ↑ Jalal ASB, Tran NT, Stevenson CE, Chan EW, Lo R, Tan X, Noy A, Lawson DM, Le TBK. Diversification of DNA-Binding Specificity by Permissive and Specificity-Switching Mutations in the ParB/Noc Protein Family. Cell Rep. 2020 Jul 21;32(3):107928. PMID:32698006 doi:10.1016/j.celrep.2020.107928