CONSTRUCTION INVITRO OF HYBRID PLASMIDS CARRYING ALL THE ECORI FRAGMENTS FROM LAMBDA-RIFD18 DNA

The cloning of all the eleven fragments obtained by degrading the phage λrifd18 by the restriction enzyme EcoRI into the plasmid pSF2124 has been achieved: nine of these fragments have been cloned individually, whereas two others have been cloned jointly in the same plasmid. These fragments harbor, in addition to λ genes, the genes for ribosomal proteins, the elongation Factor Tu, the β and β' subunits of RNA polymerase and the ribosomal RNAs. The clones carrying the ribosomal RNA genes have been constructed to provide convenient plasmids to determine the primary structure of ribosomal RNAs. Some further genetic manipulations in vitro have been performed on two of them to remove extraneous non‐ribosomal RNA gene sequences; the ribosomal genes purified this way have been subcloned into to the plasmid pBR322. Other clones of interest have been obtained which carry the genes for the elongation factor Tu, a number of 50‐S ribosomal proteins and the β subunit of RNA polymerase. Copyright © 1979, Wiley Blackwell. All rights reserved