Two Rep Genes in Small Cryptic Plasmid pKST21 of Escherichia coli

• Published in: Current microbiology Vol. 67; no. 4; pp. 437 - 441
• Main Authors: Spaková, Tímea, Fecskeová, Livia Kolesar, Javorský, Peter, Pristas, Peter
• Format: Journal Article
• Language: English
• Published: Boston Springer-Verlag 01-10-2013; Springer US; Springer Nature B.V
• Subjects: Amino Acid Sequence; Amino acids; Bacillus cereus; Bartonella tribocorum; Base Sequence; Biomedical and Life Sciences; Biotechnology; Corynebacterium renale; DNA Helicases - chemistry; DNA Helicases - genetics; E coli; Escherichia coli; Escherichia coli - chemistry; Escherichia coli - enzymology; Escherichia coli - genetics; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - genetics; gene transfer; genes; Genetic diversity; genetic variation; Life Sciences; Microbiology; Molecular Sequence Data; Open Reading Frames; Plasmids; Plasmids - chemistry; Plasmids - genetics; rumen; Selenomonas ruminantium; sequence analysis; Sequence Homology, Amino Acid; sheep; Small Plasmid; Mycobacterium Fortuitum; Replication Protein; Luria Broth; Small Cryptic Plasmid
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s00284-013-0386-6

The complete nucleotide sequence of a small cryptic plasmid pKST21 from Escherichia coli was determined. This plasmid is 1,460 bp long with an overall GC content of 51 %. Based on sequence analysis, the presence of two segments with different average GC density was observed. The segment with higher GC content revealed 98–90 % similarity to several small plasmids of E. coli and to pCR1 from Gram-positive Corynebacterium renale. Plasmid pKST21 possesses two conversely oriented open reading frames encoding proteins with a high degree of amino acid identity to Rep proteins involved in replication. ORF1 encodes replication protein similar to RepA protein of Bartonella tribocorum or Bacillus cereus plasmids or to the putative plasmid Rep protein from ecologically close Selenomonas ruminantium. ORF2 similarly encodes a replication protein, which shares 97 % homology with Rep protein from C. renale. Genetic diversity observed in plasmid pKST21 indicates a mosaic structure of the plasmid with different segments acquired from different sources. Deletion analysis showed that both fragments carrying the repA and repB genes are necessary for the replication of pKST21 in E. coli. The presence of plasmid with the same gene composition was revealed in 14 % of tested E. coli isolates from the rumen of sheep. All these strains produced identical ERIC-PCR profiles indicating isogenic origin of the strain and lack of horizontal gene transfer of pKST21 plasmid.