Halobacterium halobium Mn-SOD gene: archaebacterial and eubacterial features.

A 1.8 kb PstI fragment from Halobacterium halobium DNA was found to hybridize to synthetic oligonucleotide probes constructed by using the sequence of the N-terminus of a Mn-containing superoxide dismutase purified from H. halobium. The entire insert containing a 600-bp coding sequence for Mn-SOD and its 5' and 3' flanking regions was sequenced. The derived amino acid sequence of the structural gene showed a similarity to other manganic and iron-containing superoxide dismutases in normally conserved regions. Primer extension analysis of the H. halobium Mn-SOD mRNA showed that gene transcription begins 14 bases upstream of the translational start. A Shine-Dalgarno sequence and archaebacterial consensus promoter sequences were observed. Several other promoter and terminator nucleotide sequences homologous to prokaryotic and eukaryotic organisms were found.