PJC20 AND PJC40 - 2 HIGH-COPY-NUMBER VECTORS FOR T7 RNA POLYMERASE-DEPENDENT EXPRESSION OF RECOMBINANT GENES IN ESCHERICHIA-COLI

We report the construction of two plasmid vectors, pJC20 and pJC40, fo r the expression of recombinant genes in Escherichia coli under the co ntrol of T7 RNA polymerase. Their small sizes of ca. 2.4 kb ease the s ubcloning of large inserts and the high copy numbers obtained result i n satisfactory yields in all plasmid preparations. A multiple-cloning site offers sites for directional cloning and nested deletions. In add ition, pJC40 encodes a cleavable amino-terminal histidine tail of 10 r esidues which is added to the gene product, thus allowing purification by metal chelate chromatography. Observed expression yields are in th e range of 10% of total bacterial protein for all genes tested in our laboratory. (C) 1994 Academic Press, Inc.