We determined 5.8 kilobases of nucleotide sequence upstream of the rubredoxin encoding rubA gene of Acinetobacter calcoaceticus (Ac) ADP1. Sequence analysis revealed four open reading frames named cysD', cobQ, sodA and lysS, coding for proteins with high similarity to known sulfate adenylate transferases (partial), cobyric acid synthases, superoxide dismutases (Sod) and lysyl tRNA synthetases, respectively. Out of a large number of bacterial Sod sequences SodA of Ac ADP1 is the first member of the Fe/Mn Sod family apparently located in the periplasmic space.