DnaA protein and its binding sequence (DnaA-box) are two elements essential for the initiation of chromosomal replication in Escherichia coli and other bacteria. Recently these two elements have been found to be conserved in four Gram-positive bacteria (Bacillus subtilis, Micrococcus luteus, Mycoplasma capricolum and Streptomyces lividans). The structures of eubacterial DnaA-box regions and their locations on the chromosome and than functional aspects od DnaA protein have been compared.