title: Complete nucleotide sequence and characterization of pUA140, a cryptic plasmid from Streptococcus mutans.
abstract: Approximately 5% of strains of Streptococcus mutans contain plasmid DNA. Strain UA140 harbors a 5.6-kb cryptic plasmid, pUA140, with an overall G+C content of 32.7%. Five open reading frames (ORF), encoding peptides of larger than 100 amino acid residues, were initially designated as ORF1 to ORF5. These five ORFs were located on the same strand of pUA140. ORF1 (258 amino acids) resembled a replication protein, Rep. Upstream of the putative Rep gene, a double-stranded origin for plasmid replication that showed strong similarity to those of a number of plasmids in the pT181 family was identified. Further upstream was a region constituting the single-stranded origin of replication. A single-stranded DNA intermediate was detected during plasmid replication. Taken together, these results suggest that pUA140 replicated by the rolling circle replication mechanism but exhibited several characteristics that differ from those of other members of the pT181 plasmid family.
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Alabama at Birmingham, AL 35294, USA.
authors.forename: X
authors.initials: X
authors.lastname: Zou
authors.forename: P W
authors.initials: PW
authors.lastname: Caufield
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: F
authors.initials: F
authors.lastname: Qi
authors.forename: X
authors.initials: X
authors.lastname: Zhou
mesh_terms: D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001482:Base Composition; D001483:Base Sequence; D015139:Blotting, Southern; D004261:DNA Replication / Q000235:genetics; D004277:DNA, Single-Stranded / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D030541:Databases, Genetic; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames / Q000235:genetics; D010957:Plasmids / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D021122:Protein Subunits; D018741:Replication Origin / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013295:Streptococcus mutans / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004277:DNA, Single-Stranded; D021122:Protein Subunits