Characterization of a novel plasmid pXZ608 from Corynebacterium glutamicum

The complete nucleotide sequence of a novel cryptic plasmid pXZ608 from Corynebacterium glutamicum 227 was determined. pXZ608 was 5949 bp with six open reading frames (ORF1-6). The predicted ORF1 gene product was homologous to replication proteins of rolling circle replication plasmids. The conserved single- and double-stranded origins of rolling circle replication were found, and interestingly, the two origins were both located on ORF1, which indicated that the Rep protein encoded by ORF1 could bind to its own gene region. Deletion analysis revealed that the minimal replicon was located on the 2.14-kb SacI-BstEII fragment.