Interactions of replication initiator RctB with single- and double-stranded DNA in origin opening of Vibrio cholerae chromosome 2
| Autor: | Tatiana Venkova, Peter N Ciaccia, Soniya Chatterjee, Dhruba K. Chattoraj, Jyoti K. Jha |
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| Rok vydání: | 2020 |
| Předmět: |
DNA Replication
DNA Bacterial Replication Origin Genome Integrity Repair and Replication Biology Origin of replication medicine.disease_cause chemistry.chemical_compound Plasmid Bacterial Proteins Genetics medicine Binding site Vibrio cholerae Mutation Binding Sites Circular bacterial chromosome DNA Helicases Chromosome Gene Expression Regulation Bacterial Chromosomes Bacterial Cell biology DNA-Binding Proteins chemistry Trans-Activators DNA Protein Binding |
| Zdroj: | Nucleic Acids Res |
| ISSN: | 1362-4962 0305-1048 |
| DOI: | 10.1093/nar/gkaa826 |
| Popis: | Studies of bacterial chromosomes and plasmids indicate that their replication initiator proteins bind to origins of replication at many double-stranded sites and also at AT-rich regions where single-stranded DNA is exposed during origin opening. Single-strand binding apparently promotes origin opening by stabilizing an open structure, but how the initiator participates in this process and the contributions of the several binding sites remain unclear. Here, we show that the initiator protein of Vibrio cholerae specific to chromosome 2 (Chr2) also has single-strand binding activity in the AT-rich region of its origin. Binding is strand specific, depends on repeats of the sequence 5′ATCA and is greatly stabilized in vitro by specific double-stranded sites of the origin. The stability derives from the formation of ternary complexes of the initiator with the single- and double-stranded sites. An IHF site lies between these two kinds of sites in the Chr2 origin and an IHF-induced looping out of the intervening DNA mediates their interaction. Simultaneous binding to two kinds of sites in the origin appears to be a common mechanism by which bacterial replication initiators stabilize an open origin. |
| Databáze: | OpenAIRE |
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