Complete nucleotide sequence of the replicator region of Paracoccus (Thiobacillus) versutus pTAV1 plasmid and its correlation to several plasmids of Agrobacterium and Rhizobium species.

The complete nucleotide sequence of the replicator region of pTAV1, a cryptic, low copy number plasmid of Paracoccus versutus, was determined. The minimal replicon sequence (3149 bp) included in pTAV203/18 contains two open reading frames with coding capabilities for putative polypeptides of 23.8 (RepX) and 46 kDa (RepC'). The two genes have the same transcriptional polarity and both seem to be essential for replication of pTAV203. The predicted amino acid sequence of RepC' shows significant homology with the major replication-associated proteins of several Agrobacterium and Rhizobium plasmids. A probable origin of replication (oriV) was proposed to be localized at the 3' terminal end of the repC' gene.