New, small plasmid for Bordetella bronchiseptica - encoding only mobilisation and replication functions, for making expression vectors with broad host range and high copy number, also derived nucleic acid

摘要

New nucleic acid (I) is (1) a DNA fragment from nucleotides 1793-2452 of a 2687 base sequence (A) reproduced in the specification, encoding the polypeptide Rep, or any part of it which encodes a polypeptide involved in the replication mechanism of this nucleic acid in competent host cells or (2) a DNA fragment contg., in succesion, fragments 2500-2687 and 1-799 of (A), encoding the polypeptide MoB, or any part of it which encodes a polypeptide involved in the mobilisation mechanism of this nucleic acid between host cells. USE/ADVANTAGE - The new plasmids, which are relatively small, are useful for expressing heterologous polypeptides in a wide range of host cells, partic. in Bordetella spp. where the only known vectors are large plasmids having a low copy no. They can also be used as models for studying e.g, maintenance of replicons; host spectra; copy no. control; mobilisation etc.