A NOVEL PHASMID VECTOR IN E.COLI

摘要

Cloning and expression vectors comprise (i) a replication origin and morphogenetic signal sequence derived from filamentous bacteriophage of E.coli having F pili (f1, M13, fd) and (ii) aT7 (T7 O 10) phage promoter upstream of a multiple cloning site. The vectors carry an antibiotic resistance marker gene ampicillin (pARC032 and pARC035) or Kanamycin (pARC036) and a bacterial origin of replication pARC032 and pARC035 are identically constructed except the f1 replication origin sequence lies in opposite orientation. Upon transformation of E.coli male specific strains with phasmid containing a recombinant insert, is plasmid DNA packaged as a viral particle can be produced when the transformants are superinfected with a helper phage. This ss phasmid DNA can also be used as template for ss DNA sequencing and in vitro site directed mutagenesis. Genes inserted at the multiple cloning site of the phasmids can be expressed in appropriate host strains.