This family consists of the RepA1 leader peptides. The frequency of replication of IncFII plasmid NR1 during the cell division cycle is regulated by the control of the synthesis of the plasmid-specific replication initiation protein (RepA1). When RepA1 is synthesized, it binds to the plasmid replication origin (ori) and effects the assembly of a replication complex composed of host proteins that mediate the replication of the plasmid. The tap gene encodes a 24-amino acids protein. The translation of tap is required for translation of repA.