Initiation mechanisms in replication of filamentous phage DNA.
Filamentous phage DNA replication occurs in two steps. First, an RNA-primed minus strand is made on the plus strand. Then, a new plus strand is made on the resulting double strand. The RNA primer which initiates synthesis of the minus strand is produced at a specific site on the plus strand template by the host RNA polymerase holoenzyme. Despite a lack of sequences similar to the promoter consensus, the DNA replication origin has a much higher affinity for the holoenzyme than the transcriptional promoters. The non-template strand of the single-stranded -10 region of the origin appears to be responsible for this high affinity. The recognition mechanisms seem to share common features with those in transcriptional promoters. Plus-strand synthesis is initiated by a specific nick introduced into the negatively supercoiled replicative form by the phage-encoded initiator protein. The nicking reaction is preceded by an ordered series of protein-induced DNA conformational changes.
Horiuchi
K
K
Laboratory of Molecular Genetics and Immunology, The Rockefeller University, New York, NY 10021, USA. horiuck@rockvax.rockefeller.edu
D001435:Bacteriophages / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis; D008969:Molecular Sequence Data; D014779:Virus Replication / Q000235:genetics* / Q000502:physiology*
D004279:DNA, Viral