Insights into the genetic organization of the Corynebacterium diphtheriae erythromycin resistance plasmid pNG2 deduced from its complete nucleotide sequence

Plasmid. 2003 Jan;49(1):63-74. doi: 10.1016/s0147-619x(02)00115-4.


The complete nucleotide sequence of the erythromycin resistance plasmid pNG2 from the human pathogen Corynebacterium diphtheriae S601 was determined. The plasmid has a total size of 15,100 bp and contains at least 17 coding regions. Comparative genomics identified conserved motifs within replication initiator proteins of corynebacterial plasmids and a novel nucleotide sequence feature, termed 22-bp box, located downstream of the repA gene. The erythromycin resistance determinant erm(X) is flanked by inverted repeats of the novel insertion sequence IS3504, which may be responsible for a spontaneous deletion of the antibiotic resistance gene region. Furthermore, pNG2 encodes a putative conjugative relaxase, a membrane protein of the natural resistance-associated macrophage protein (Nramp) family and a protein with Nudix hydrolase signature. Expression of the predicted coding regions of pNG2 in Escherichia coli JM109 was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) assays. The detailed annotation of the entire pNG2 sequence provided genetic information regarding its molecular evolution and its role in dissemination of antibiotic resistance genes by horizontal gene transfer.

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Conserved Sequence
  • Corynebacterium diphtheriae / drug effects
  • Corynebacterium diphtheriae / genetics*
  • DNA Helicases / genetics
  • DNA Nucleotidyltransferases / genetics
  • DNA Transposable Elements
  • DNA, Intergenic
  • DNA-Binding Proteins*
  • Drug Resistance, Bacterial / genetics*
  • Erythromycin / pharmacology
  • Escherichia coli / genetics
  • Gene Order
  • Molecular Sequence Data
  • Plasmids / genetics*
  • Proteins / genetics
  • Pyrophosphatases / genetics
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Trans-Activators*


  • Bacterial Proteins
  • DNA Transposable Elements
  • DNA, Intergenic
  • DNA-Binding Proteins
  • Proteins
  • Trans-Activators
  • replication initiator protein
  • Erythromycin
  • DNA Nucleotidyltransferases
  • DNA relaxase
  • Pyrophosphatases
  • nudix hydrolase Orf135
  • DNA Helicases

Associated data

  • GENBANK/AF492560