A host-encoded DNA-binding protein promotes termination of plasmid replication at a sequence-specific replication terminus.
We have purified approximately 6600-fold an approximately 40-kDa protein (Ter protein) encoded by Escherichia coli that specifically binds to two sites at the 216-base-pair replication terminus (tau) of the plasmid R6K. Chemical footprinting experiments have shown that the Ter protein binds to two 14- to 16-base-pair sequences that exist as inverted repeats in the tau fragment. Site-directed mutagenesis of one of the terminus sequences (tau R) resulted in a mutant tau R that failed to bind to the Ter protein. The same mutant terminus also failed to terminate DNA replication in vivo. These experiments strongly suggest that the interaction of the Ter protein with tau sequences plays an essential role in the termination of DNA replication, specifically at tau.
Sista
P R
PR
Department of Microbiology and Immunology, Duke University Medical Center, Durham, NC 27710.
Mukherjee
S
S
Patel
P
P
Khatri
G S
GS
Bastia
D
D
D001483:Base Sequence; D001973:Bromodeoxyuridine; D003001:Cloning, Molecular; D003432:Cross-Linking Reagents; D015342:DNA Probes; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015246:Deoxyribonuclease EcoRI; D015247:Deoxyribonuclease HindIII; D015252:Deoxyribonucleases, Type II Site-Specific; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D010957:Plasmids
D003432:Cross-Linking Reagents; D015342:DNA Probes; D004268:DNA-Binding Proteins; D015246:Deoxyribonuclease EcoRI; D015247:Deoxyribonuclease HindIII; D015252:Deoxyribonucleases, Type II Site-Specific; C024403:GGCC-specific type II deoxyribonucleases; D001973:Bromodeoxyuridine