Patent ID: 6337208
Filing Date: 2002-01-08
Classification: C12N

Abstract:
An Escherichia coli cloning vector comprising(a) a nucleic acid sequence encoding a modified polypeptide which is lethal for an E. coli cell operatively linked to a regulatable expression control sequence, wherein said polypeptide is selected from the Anabaena flos-aquae GvpA protein (Genbank accession No. M32060) or a polypeptide homologous thereto, wherein said homologous polypeptide has an identity of more than 90% to the GvpA protein, and (b) at least one cloning site comprising a multiple non-naturally occurring cloning site located within the sequence encoding the modified protein, wherein insertion of a foreign nucleic acid insert in the cloning site causes a disruption of the expression of the lethal polypeptide; wherein the lethal polypeptide is encoded by (i) the nucleotide sequence encoding the Anabaena flos-aquea GvpA protein (Genbank accession No. M32060), (ii) a nucleotide sequence corresponding to the sequence of (i) within the scope of the degeneracy of the genetic code or (iii) a nucleotide sequence hybridizing with the sequence of (i) and/or (ii) under stringent conditions which comprise washing for 1 hour with 1.0Ã—SSC and 0.1% SDS at 50Â° C.