Abstract: Microbiological methods, compositions and transformants are used for production of organic products for controlling cellular properties. Extrachromosomal elements are used which are subject to external modulation for production of a control element. The change in the amount of production of the control element allows for enhanced expression of a gene producing a poly(amino acid) product. The change in production of the control element allowing for enhanced gene expression of the product is accompanied by amplification of the product producing gene.

Abstract: A method and a DNA linker are described for synthesizing relatively long double-stranded deoxyribonucleic acid sequences of defined composition. Short complementary single strand segments of oligonucleotides comprising part of the full sequence desired are synthesized using known procedures. Overlapping single strand segments are annealed forming double-stranded fragments which are inserted in cloning vectors and cloned in an appropriate host, both purifying the DNA fragments and amplifying the amount thereof. An adjacent fragment is then similarly synthesized in quantity and such fragments are inserted adjacent to the first synthetic introduced fragments in the cloning vectors, followed by cloning in an appropriate host. The procedure continues until the entire desired sequence has been formed, at which time it may be excised or cloned directly in the vectors upon which it was made.

Abstract: Method and compositions are provided for replication and expression of exogenous genes in microorganisms. Plasmids or virus DNA are cleaved to provide linear DNA having ligatable termini to which is inserted a gene having complementary termini, to provide a biologically functional replicon with a desired phenotypical property. The replicon is inserted into a microorganism cell by transformation. Isolation of the transformants provides cells for replication and expression of the DNA molecules present in the modified plasmid. The method provides a convenient and efficient way to introduce genetic capability into microorganisms for the production of nucleic acids and proteins, such as medically or commercially useful enzymes, which may have direct usefulness, or may find expression in the production of drugs, such as hormones, antibiotics, or the like, fixation of nitrogen, fermentation, utilization of specific feedstocks, or the like.