Abstract: A fusion protein including a ballast portion and a desired protein. The ballast portion forms either the C- or N-terminus of the fusion protein, and the ballast portion includes a part of the amino acid sequence of interleukin-2 (IL-2). According to certain preferred embodiments, the ballast portion includes approximately the first 100 amino acids of IL-2. According to other preferred embodiments, the ballast portion contains fewer than 100 amino acids of IL-2. According to further advantageous embodiments, a synthetic IL-2 gene is divided by unique cleavage sites into 6 segments, any number of these segments can be linked in arbitrary sequence. These embodiments permit specific instructions with which the solubility of the fusion protein can be altered, and thus the fusion proteins can readily be separated from soluble proteins intrinsic to a host. The DNA coding for the fusion proteins, as well as vectors and hosts are also provided.

Abstract: The phosphinothricin (PTC)-resistance gene isolated from the genome of Streptomyces viridochromogenes DSM 40736 is, after adaptation to the codon usage in plants, synthesized and incorporated into gene structures which make plants resistant to PTC after expression therein.