Functional expression of the yeast Mn-superoxide dismutase gene in Escherichia coli requires deletion of the signal peptide sequence.

Oligodeoxyribonucleotide-directed mutagenesis has been used to delete the leader sequence-coding region from the yeast gene specifying Mn-superoxide dismutase and thus enable its expression in Escherichia coli. The deletion of this leader was demonstrated to be an absolute requirement for the synthesis of an active yeast enzyme in the bacterium. Complementation analysis in E. coli has confirmed that the product of the truncated yeast gene is active in vivo as well as in vitro.