The DNA sequence of pC2A. The complete 5467-bp DNA sequence is shown (also see Fig. 2). Selected restriction sites are underlined. Four ORFs, ssrA, repA, orf1, and orf2, of greater than 120 aa were observed in the sequence. Their orientation is shown by the small arrows. The amino acid sequences of the putative proteins encoded by these ORFs are shown below the corresponding DNA sequences. The HUHUU (U = bulky hydrophobic residues) motif conserved among the Rep proteins of rolling circle plasmids (31) was identified in the RepA protein (heavy underline). Two long direct repeats of 64 bp (A) and 56 bp (B), and a 20-bp perfect inverted repeat which may play a role in plasmid replication were noted in the intergenic region between ssrA and repA.