Pseudomonad replication origins: a paradigm for bacterial origins?

Structural features of three analysed bacterial DNA replication origin classes (six enteric origins, three pseudomonad origins, and the Bacillus subtilis origin region) are compared in order to deduce characteristics common to all bacterial origins and characteristics that distinguish the three origin classes. The two Pseudomonas aeruginosa origins are shown to map within 10 kb of each other, and correlations are drawn with four potential origin regions in B. subtilis. The enteric origin class is further distinguished from the other two classes by its genetic organization, the presence of GATC sites, and the role of Dam methylation in enteric initiation. The pseudomonad origin class has the most features that are common to all of these bacterial origins, and hence may be the paradigm bacterial origin class.