Characterization of pR18, a novel rolling-circle replication plasmid from Lactobacillus plantarum.
Lactobacillus plantarum PA18, a strain originally isolated from the leaves of Pandanus amaryllifolius, contains a pR18 plasmid. The pR18 plasmid is a 3211bp circular molecule with a G+C content of 35.8%. Nucleotide sequence analysis revealed two putative open reading frames, ORF1 and ORF2, in which ORF2 was predicted (317 amino acids) to be a replication protein and shared 99% similarity with the Rep proteins of pLR1, pLD1, pC30il, and pLP2000, which belong to the RCR pC194/pUB110 family. Sequence analysis also indicated that ORF1 was predicted to encode linA, an enzyme that enzymatically inactivates lincomycin. The result of Southern hybridization and mung bean nuclease treatment confirmed that pR18 replicated via the RCR mechanism. Phylogenetic tree analysis of pR18 plasmid proteins suggested that horizontal transfer of antibiotic resistance determinants without genes encoding mobilization has not only occurred between Bacillus and Lactobacillus but also between unrelated bacteria. Understanding this type of transfer could possibly play a key role in facilitating the study of the origin and evolution of lactobacillus plasmids. Quantitative PCR showed that the relative copy number of pR18 was approximately 39 copies per chromosome equivalent.
Department of Cell and Molecular Biology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Electronic address: Tannaz.jalilsood@yahoo.com.
Tannaz
T
Jalilsood
Department of Cell and Molecular Biology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Ali
A
Baradaran
Department of Bioprocess Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Foo Hooi
FH
Ling
Department of Microbiology, Faculty Biotechnology and Biomolecular Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Shuhaimi
S
Mustafa
Department of Cell and Molecular Biology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Khatijah
K
Yusof
Department of Cell and Molecular Biology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia; Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia. Electronic address: raha@upm.edu.my.
Raha Abdul
RA
Rahim
D001483:Base Sequence; D015139:Blotting, Southern; D004261:DNA Replication; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics*; D004270:DNA, Circular / Q000032:analysis / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000032:analysis / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D018628:Gene Dosage; D048191:Lactiplantibacillus plantarum / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids / Q000032:analysis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018741:Replication Origin
D004269:DNA, Bacterial; D004270:DNA, Circular; D004277:DNA, Single-Stranded
Cryptic plasmid; Lactobacillus plantarum; Rep; linA; qPCR