Back to Search
Start Over
DNA phase transition promoted by replication initiator.
- Source :
-
Biochemistry [Biochemistry] 2000 Aug 08; Vol. 39 (31), pp. 9139-45. - Publication Year :
- 2000
-
Abstract
- DNA is flexible and easily subjected to bending and wrapping via DNA/protein interaction. DNA supercoiling is known to play an important role in a variety of cellular events, such as transcription, replication, and recombination. It is, however, not well understood how the superhelical strain is efficiently redistributed during these reactions. Here we demonstrate a novel property of an initiator protein in DNA relaxation by utilizing a one-molecule-imaging technique, atomic force microscopy, combined with biochemical procedures. A replication initiator protein, RepE54 of bacterial mini-F plasmid (2.5 kb), binds to the specific sequences (iterons) within the replication region (ori2). When RepE54 binds to the iterons of the negatively supercoiled mini-F plasmid, it induces a dynamic structural transition of the plasmid to a relaxed state. This initiator-induced relaxation is mediated neither by the introduction of a DNA strand break nor by a local melting of the DNA double strand. Furthermore, RepE54 is not wrapped by DNA repeatedly. These data indicate that a local strain imposed by initiator binding can induce a drastic shift of the DNA conformation from a supercoiled to a relaxed state.
- Subjects :
- Adenosine Triphosphate chemistry
Bacterial Proteins ultrastructure
DNA Helicases ultrastructure
DNA Topoisomerases, Type I chemistry
DNA, Bacterial ultrastructure
DNA, Circular chemistry
DNA, Superhelical chemistry
DNA, Superhelical ultrastructure
DNA-Binding Proteins ultrastructure
F Factor chemistry
Microscopy, Atomic Force
Nucleoproteins chemistry
Plasmids chemistry
Plasmids ultrastructure
Protein Binding
Repressor Proteins ultrastructure
Trans-Activators ultrastructure
Bacterial Proteins chemistry
DNA Helicases chemistry
DNA Replication
DNA, Bacterial chemistry
DNA-Binding Proteins chemistry
Escherichia coli Proteins
Repressor Proteins chemistry
Trans-Activators chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0006-2960
- Volume :
- 39
- Issue :
- 31
- Database :
- MEDLINE
- Journal :
- Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 10924107
- Full Text :
- https://doi.org/10.1021/bi0003588