Analysis of plasmid pDBORO – A plasmid encoding an orotate transporter from Lactococcus lactis subsp. lactis biovar. diacetylactis strain DB0410
Special Symposium - Innovations in Food Technology (LMC Congress)
Innovations in Food Technology - Poster Session (LMC/Food - P1)
Keywords: plasmid, DNA replication, lactic acid bacteria
A new lactococcal plasmid, pDBORO, was isolated from the Lactococcus lactis ssp. lactis biovar diacetylactis strain DB0410 responsible for the sensitivity of DB0410 towards the pyrimidine-analog 5´-fluoroorotate. The plasmid pDBORO amounts to 16404 bp and its complete nucleotide sequence has been determined.
Fifteen open reading frames (ORFs) were encountered of which three insertion-sequence (IS) elements identified as two IS946 and one IS982. Two ORFs are incomplete due to the insertion of an IS element in their carboxy terminal end. Homologs for four ORFs were found on the IL1403 sequence: the copB gene, coding for a copper-potassium transporting ATPaseB and the ysbA, ysbB and ysbC genes.
The structural organization of the pDBORO replication region is highly similar to other theta-replicating plasmids both at the cis- (repA) and trans-acting (repB) sequences.
By plasmid deletion analysis and molecular cloning, we identified the open reading frames on pDBORO necessary for the utilization of orotate as the sole pyrimidine source. Surprisingly, homologs are found on the Lactococcus lactis IL1403 and MG1363 chromosomes despite the fact that they are resistant towards fluoroorotate.
Presented Wednesday 19, 13:30 to 15:00, in session Innovations in Food Technology - Poster Session (LMC/Food - P1).
