One of two hemN genes in Bradyrhizobium japonicum is functional during anaerobic growth and in symbiossi

Previously, we screened the symbiotic gene region of the Bradyhizobium japonicum chromosome for new NifA-dependent genes by competitive DNA-RNA hybridization (A. Nienaber, A. Huber, M. Gottfert, H. Hennecke, and H. M. Fischer, J. Bacteriol. 182:1472-1480, 2000). Here we report more details on one of the genes identified, a hemN-like gene (now called hemN1) whose product exhibits significant similarity to oxygen-independent coproporphyrinogen III dehydrogenases involved in heme biosynthesis in facultatively anaerobic bacteria.