Families of orc/cdc6 -associated replication origins in the haloarchaeal genomes. A. Phylogenetic tree of origin-associated Orc/Cdc6 homologs (Hbo: Halogeometricum borinquense, Hhi: Haloarcula hispanica, Hje: Halalkalicoccus jeotgali B3, Hla: Halorubrum lacusprofundi, Hma: Haloarcula marismortui, Hmu: Halomicrobium mukohataei, HR1: Halobacterium salinarum R1, Htu: Haloterrigena turkmenica, Hut: Halorhabdus utahensis, Hvo: Haloferax volcanii DS2, Hwa: Haloquadratum walsbyi, Nma: Natrialba magadii, Nph: Natronomonas pharaonis, NRC-1: Halobacterium sp. NRC-1). * indicates the Orc/Cdc6 proteins encoded on extrachromosomal elements. Orc/Cdc6 proteins from other archaea (APE: Aeropyrum pernix, Pab: Pyrococcus abyssi, Sso: Sulfolobus solfataricus) are highlighted with yellow background. The origin conserved in all genomes was assigned the name oriC1, as in previous reports (in red), and the other two origin clusters with the top two members, excluding oriC1 in this study, were assigned the names oriCa (in blue) and oriCb (in pink). B. Logo representations of the putative ORB elements identified in the predicted replication origins adjacent to the orc/cdc6 genes. The ORB elements are not shown for origin families with only one member.