The interaction of RepC initiator with iterons in the replication of the broad host-range plasmid RSF1010.
The replication origin of the broad host-range plasmid RSF1010 contains 3.5 copies of a 20mer iteron sequence that bind specifically to the plasmid-encoded initiator, RepC. Here we demonstrated that even a single iteron was bent upon binding of RepC. Moreover, the bending angle seems to become larger along with the increment of the number of iterons. In a mutational analysis of the iteron sequence, we isolated seven kinds of base-substitution mutants of iterons, and estimated the replication activity of these mutants in vivo. We found that each of the subsections in the 20mer iteron sequence made a distinct contribution to the initiation of RSF1010 DNA replication. With the binding assay of RepC and mutated iterons in vitro, we found that the formation of a productive RepC-iteron complex was required for the initiation of plasmid DNA replication.
Miao
D M
DM
Department of Agricultural Chemistry, Kyoto University, Japan.
Sakai
H
H
Okamoto
S
S
Tanaka
K
K
Okuda
M
M
Honda
Y
Y
Komano
T
T
Bagdasarian
M
M
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D004261:DNA Replication / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000096:biosynthesis* / Q000235:genetics*; D011485:Protein Binding; D018741:Replication Origin
D001426:Bacterial Proteins; D004269:DNA, Bacterial; C043650:RepC protein, Staphylococcus aureus