The complete sequence of the Fe2+ -containing superoxide dismutase (Fe-SOD)-encoding gene of Chlamydomonas reinhardtii was determined from genomic DNA by use of the direct (PCR) and inverse PCR (IPCR). It was confirmed by reverse transcription-PCR. Primers employed in the PCR represented oligodeoxyribonucleotides corresponding to conserved amino acid (aa) residues of Fe-SOD. From the sequence of direct PCR product, primers were designed for IPCR. All amplified fragments were cloned and sequenced. Analysis of Fe-SOD reveals that the open reading frame consists of 234 aa which show a high degree of homology to other Fe-SOD. The first 33 aa are predominantly either hydrophobic or basic, and may serve as the signal peptide for this chloroplastic protein. Potential transcription start points and eukaryotic control elements, as well as a polyadenylation site, were identified.