Initiation protein induced helix destabilization at the lambda origin: a prepriming step in DNA replication.
The interaction of the lambda phage initiator protein, O, with the lambda origin sequence, ori, has been investigated. Binding of O, or its amino-terminal fragment, causes a major structural change within a 60 bp AT-rich region just to the right of the O-binding site. ATP or other molecular energy sources are not required. The modification, as assayed by nuclease sensitivity, is reduced when certain ori mutant sequences, which bind O but fail to replicate, are substituted for the wild-type sequence. The modification of DNA structure caused by the interaction of O is absolutely dependent on the presence of superhelical tension at the lambda origin sequence, and has several properties consistent with a strand separation reaction. We propose that this modification is a fundamental prepriming event that is the first stage in initiation of bidirectional replication in lambda after O binding.
Schnos
M
M
Institute for Molecular Virology, University of Wisconsin-Madison 53706.
Zahn
K
K
Inman
R B
RB
Blattner
F R
FR
D010582:Bacteriophage lambda / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004277:DNA, Single-Stranded; D004278:DNA, Superhelical / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015246:Deoxyribonuclease EcoRI; D004720:Endonucleases; D008969:Molecular Sequence Data; D009691:Nucleic Acid Denaturation; D009708:Nucleotidases; D012091:Repetitive Sequences, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014764:Viral Proteins / Q000378:metabolism*; D014779:Virus Replication
C024013:DNA replication complex protein, Bacteriophage lambda; D004277:DNA, Single-Stranded; D004278:DNA, Superhelical; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D014764:Viral Proteins; D004720:Endonucleases; D004262:DNA Restriction Enzymes; D015246:Deoxyribonuclease EcoRI; D009708:Nucleotidases; D015719:Single-Strand Specific DNA and RNA Endonucleases