| abstract |
Disclosed is the novel plasmid pVE1, deletion mutants thereof, recombinant derivatives thereof, which is the same as the genome or nucleic acid of such plasmids and derivatives of such genome, which are useful as rDNA cloning vectors into host organisms, such as bacteria, for example, Streptomyces avermitilis; portions of such plasmid genome are additionally useful as adjuncts in recombinant DNA cloning procedures, for example: 1.) to permit the maintenance of cloned DNA in the host, either in an integrated state or as an autonomous element; 2.) to serve as promoters for increasing expression of endogenous or foreign genes wherein said promoters are ligated to such genes or otherwise serve as promoters; and 3.) to serve as regulatory elements for achieving control over endogenous and foreign gene expression; as cloning vectors, pVE1 its deletion mutants, and other derivatives serve for the amplification and transfer of DNA sequences (genes) coding for useful functions, for example, genes necessary for the production of the anthelmintic avermectin, or genes necessary for the production of hepatitis B antigen, and of DNA sequences which are useful per se, for example, distinct plasmid vectors which are inherently useful; such modified cloning vectors hybrid DNA molecules comprising the pVE1 genome or portions thereof and foreign DNA sequence) are introduced into the recipient organism by conjugation or transformation; wherein the hybrid DNA functions in an integrated mode and/or in a plasmid mode. Also disclosed are microorganisms comprising pVE1 plasmid and deletion and hybrid (chimeric) derivatives thereof; and microorganisms comprising hybrid (chimeric) plasmid-plasmids and derivatives thereof. |