| abstract |
A DNA sequence whose +strand consists of the nucleotides (I) wherein Y1?...Ym? represents a promotor with one or more restriction enzyme sites, m being an integer corresponding to the number of base pairs in the promotor, each X as well as Z, V and W is an arbitrary one of the nucleotides A, G, C or T, and the index n is an integer from 3 to 12, with the proviso that X1?-Xn? cannot contain a start codon. This DNA sequence, together with the gene to be expressed, may be introduced into an ordinary replicable cloning medium, such as a plasmid and be transferred to a micro-organism which produces the desired protein in a high yield by cultivation on a substrate. |